This page has only limited features, please log in for full access.
The current work proposed the application of methylammonium lead iodide (MAPbI3) perovskite microrods toward photo resistor switches. A metal-semiconductor-metal (MSM) configuration with a structure of silver-MAPbI3(rods)-silver (Ag/MAPbI3/Ag) based photo-resistor was fabricated. The MAPbI3 microrods were prepared by adopting a facile low-temperature solution process, and then an independent MAPbI3 microrod was employed to the two-terminal device. The morphological and elemental compositional studies of the fabricated MAPbI3 microrods were performed using FESEM and EDS, respectively. The voltage-dependent electrical behavior and electronic conduction mechanisms of the fabricated photo-resistors were studied using current–voltage (I–V) characteristics. Different conduction mechanisms were observed at different voltage ranges in dark and under illumination. In dark conditions, the conduction behavior was dominated by typical trap-controlled charge transport mechanisms within the investigated voltage range. However, under illumination, the carrier transport is dominated by the current photogenerated mechanism. This study could extend the promising application of perovskite microrods in photo-induced resistor switches and beyond.
Ehsan Raza; Fakhra Aziz; Arti Mishra; Noora Al-Thani; Zubair Ahmad. MAPbI3 Microrods-Based Photo Resistor Switches: Fabrication and Electrical Characterization. Materials 2021, 14, 4385 .
AMA StyleEhsan Raza, Fakhra Aziz, Arti Mishra, Noora Al-Thani, Zubair Ahmad. MAPbI3 Microrods-Based Photo Resistor Switches: Fabrication and Electrical Characterization. Materials. 2021; 14 (16):4385.
Chicago/Turabian StyleEhsan Raza; Fakhra Aziz; Arti Mishra; Noora Al-Thani; Zubair Ahmad. 2021. "MAPbI3 Microrods-Based Photo Resistor Switches: Fabrication and Electrical Characterization." Materials 14, no. 16: 4385.
This work intends to investigate the optimum sintering method and temperature that can improve the efficiency of bismuth telluride cold compact pellets, for the thermoelectric applications. Different p-type and n-type bismuth telluride cold compact pellets were treated using three different sintering techniques and conditions: pressure less (conventional), microwave, and tube (using argon environment) at temperatures 250 °C, 300 °C, 350 °C, and 400 °C. The structural, microscopic, electron transport, thermal, and dielectric properties of the pristine and sintered samples were examined. Broadband dielectric spectroscopy was performed to extract a detailed picture of the dielectric properties of the samples. Even though each type of sintering had its own merits and demerits, the optimum conditions for enhanced electric and thermal features were found in microwave furnace followed by tube and conventional. Low thermal conductivity of 0.4 W/m/K was observed in the samples sintered at 250 °C while the increase in sintering temperature from 250 °C to 300 °C improved the crystallinity of the material. Moreover, the crystal structure of the bismuth telluride altered with the occurrence of higher oxidation leading to the formation of high bismuth telluride oxide phases at sintering temperatures above 300 °C, more dominantly in the n-type samples.
Farheen F. Jaldurgam; Zubair Ahmad; Farid Touati; Abdulla Al Ashraf; Abdul Shakoor; Jolly Bhadra; Noora J. Al-Thani; Dong Suk Han; Talal Altahtamouni. Optimum sintering method and temperature for cold compact Bismuth Telluride pellets for thermoelectric applications. Journal of Alloys and Compounds 2021, 877, 160256 .
AMA StyleFarheen F. Jaldurgam, Zubair Ahmad, Farid Touati, Abdulla Al Ashraf, Abdul Shakoor, Jolly Bhadra, Noora J. Al-Thani, Dong Suk Han, Talal Altahtamouni. Optimum sintering method and temperature for cold compact Bismuth Telluride pellets for thermoelectric applications. Journal of Alloys and Compounds. 2021; 877 ():160256.
Chicago/Turabian StyleFarheen F. Jaldurgam; Zubair Ahmad; Farid Touati; Abdulla Al Ashraf; Abdul Shakoor; Jolly Bhadra; Noora J. Al-Thani; Dong Suk Han; Talal Altahtamouni. 2021. "Optimum sintering method and temperature for cold compact Bismuth Telluride pellets for thermoelectric applications." Journal of Alloys and Compounds 877, no. : 160256.
Thermoelectricity is a promising technology that directly converts heat energy into electricity and finds its use in enormous applications. This technology can be used for waste heat recovery from automobile exhausts and industrial sectors and convert the heat from solar energy, especially in hot and humid areas such as Qatar. The large-scale, cost-effective commercialization of thermoelectric generators requires the processing and fabrication of nanostructured materials with quick, easy, and inexpensive techniques. Moreover, the methods should be replicable and reproducible, along with stability in terms of electrical, thermal, and mechanical properties of the TE material. This report summarizes and compares the up-to-date technologies available for batch production of the earth-abundant and ecofriendly materials along with some notorious works in this domain. We have also evaluated and assessed the pros and cons of each technique and its effect on the properties of the materials. The simplicity, time, and cost of each synthesis technique have also been discussed and compared with the conventional methods.
Farheen Jaldurgam; Zubair Ahmad; Farid Touati. Synthesis and Performance of Large-Scale Cost-Effective Environment-Friendly Nanostructured Thermoelectric Materials. Nanomaterials 2021, 11, 1091 .
AMA StyleFarheen Jaldurgam, Zubair Ahmad, Farid Touati. Synthesis and Performance of Large-Scale Cost-Effective Environment-Friendly Nanostructured Thermoelectric Materials. Nanomaterials. 2021; 11 (5):1091.
Chicago/Turabian StyleFarheen Jaldurgam; Zubair Ahmad; Farid Touati. 2021. "Synthesis and Performance of Large-Scale Cost-Effective Environment-Friendly Nanostructured Thermoelectric Materials." Nanomaterials 11, no. 5: 1091.
This article presents recent research directions in the study of Earth-abundant, cost-effective, and low-toxic advanced nanostructured materials for thermoelectric generator (TEG) applications. This study’s critical aspect is to systematically evaluate the development of high-performance nanostructured thermoelectric (TE) materials from sustainable sources, which are expected to have a meaningful and enduring impact in developing a cost-effective TE system. We review both the performance and limitation aspects of these materials at multiple temperatures from experimental and theoretical viewpoints. Recent developments in these materials towards enhancing the dimensionless figure of merit, Seebeck coefficient, reduction of the thermal conductivity, and improvement of electrical conductivity have also been discussed in detail. Finally, the future direction and the prospects of these nanostructured materials have been proposed.
Farheen Jaldurgam; Zubair Ahmad; Farid Touati. Low-Toxic, Earth-Abundant Nanostructured Materials for Thermoelectric Applications. Nanomaterials 2021, 11, 895 .
AMA StyleFarheen Jaldurgam, Zubair Ahmad, Farid Touati. Low-Toxic, Earth-Abundant Nanostructured Materials for Thermoelectric Applications. Nanomaterials. 2021; 11 (4):895.
Chicago/Turabian StyleFarheen Jaldurgam; Zubair Ahmad; Farid Touati. 2021. "Low-Toxic, Earth-Abundant Nanostructured Materials for Thermoelectric Applications." Nanomaterials 11, no. 4: 895.
Sports has the potential to integrate with different scientific subjects, including materials science and engineering, making it an ideal approach to enhance the students’ affinity toward sustainable education in science, technology, engineering, and mathematics (STEM). Amid gradual educational reformations in the state of Qatar, a distinctive STEM program titled, “Science in Sports” (SIS) was launched to investigate STEM integrated learning in secondary school students. The participant students, 248 students (112 females and 136 males) from 15 different government-operated (public) secondary schools, from rural and urban areas, were given STEM workshops on one of the sports materials, during this pilot study, resultantly challenging them to engineer a sports product. The study employed a mixed-method study in which quantitative approaches were applied to analyze the program effectiveness, with a t-test statistical analysis performed over data collected from a period of five continuous years from 2012 to 2017 in five different cycles. A more dominant data collection included pre and post surveys, substantiating observations of the program facilitator and their schoolteachers were included in this research and development (R&D) study to review the student learning behavior for a qualitative approach. Moreover, the results of the strength, weakness, opportunities, and threats (SWOT) analysis provided an overview of the program’s effectiveness in implicating the engagement of the students in exhibiting their prototypical skills in engineering sports products along with STEM literacy. Apart from understanding the scientific concepts/principles applied in simple sports applications, student attitudes toward STEM fields augmented, as witnessed by the student productivity.
Ruba Ali; Jolly Bhadra; Nitha Siby; Zubair Ahmad; Noora Al-Thani. A STEM Model to Engage Students in Sustainable Science Education through Sports: A Case Study in Qatar. Sustainability 2021, 13, 3483 .
AMA StyleRuba Ali, Jolly Bhadra, Nitha Siby, Zubair Ahmad, Noora Al-Thani. A STEM Model to Engage Students in Sustainable Science Education through Sports: A Case Study in Qatar. Sustainability. 2021; 13 (6):3483.
Chicago/Turabian StyleRuba Ali; Jolly Bhadra; Nitha Siby; Zubair Ahmad; Noora Al-Thani. 2021. "A STEM Model to Engage Students in Sustainable Science Education through Sports: A Case Study in Qatar." Sustainability 13, no. 6: 3483.
An unprecedented turn in educational pedagogies due to the COVID-19 pandemic has significantly affected the students’ learning process worldwide. This article describes developing a STEM-based online course during the schools’ closure in the COVID-19 epidemic to combat the virtual science classroom’s limitations that could promise an active STEM learning environment. This learning model of the online STEM-based course successfully developed and exercised on 38 primary–preparatory students helped them to overcome the decline in their learning productivity. Various digital learning resources, including PowerPoint presentations, videos, online simulations, interactive quizzes, and innovative games, were implemented as instructional tools to achieve the respective content objectives. A feedback mechanism methodology was executed to improve online instructional delivery and project learners’ role in a student-centered approach, thereby aiding in the course content’s qualitative assessment. The students’ learning behavior provided concrete insights into the program’s positive outcomes, witnessing minimal student withdrawals and maximum completed assignments. Conclusions had been drawn from the course assessment (by incorporating both synchronous and asynchronous means), student feedback, and SWOT analysis to evaluate the course’s effectiveness.
Azza Abouhashem; Rana Abdou; Jolly Bhadra; Nitha Siby; Zubair Ahmad; Noora Al-Thani. COVID-19 Inspired a STEM-Based Virtual Learning Model for Middle Schools—A Case Study of Qatar. Sustainability 2021, 13, 2799 .
AMA StyleAzza Abouhashem, Rana Abdou, Jolly Bhadra, Nitha Siby, Zubair Ahmad, Noora Al-Thani. COVID-19 Inspired a STEM-Based Virtual Learning Model for Middle Schools—A Case Study of Qatar. Sustainability. 2021; 13 (5):2799.
Chicago/Turabian StyleAzza Abouhashem; Rana Abdou; Jolly Bhadra; Nitha Siby; Zubair Ahmad; Noora Al-Thani. 2021. "COVID-19 Inspired a STEM-Based Virtual Learning Model for Middle Schools—A Case Study of Qatar." Sustainability 13, no. 5: 2799.
Perovskite solar cells (PSCs) expressed great potentials for offering a feasible alternative to conventional photovoltaic technologies. 2D/3D hybrid PSCs, where a 2D capping layer is used over the 3D film to avoid the instability issues associated with perovskite film, have been reported with improved stabilities and high power conversion efficiencies (PCE). However, the profound analysis of the PSCs with prolonged operational lifetime still needs to be described further. Heading towards efficient and long-life PSCs, in-depth insight into the complicated degradation processes and charge dynamics occurring at PSCs' interfaces is vital. In particular, the Au/HTM/perovskite interface got a substantial consideration due to the quest for better charge transfer; and this interface is debatably the trickiest to explain and analyze. In this study, multiple characterization techniques were put together to understand thoroughly the processes that occur at the Au/HTM/perovskite interface. Inquest analysis using current–voltage (I–V), electric field induced second harmonic generation (EFISHG), and impedance spectroscopy (IS) was performed. These techniques showed that the degradation at the Au/HTM/perovskite interface significantly contribute to the increase of charge accumulation and change in impedance value of the PSCs, hence resulting in efficiency fading. The 3D and 2D/3D hybrid cells, with PCEs of 18.87% and 20.21%, respectively, were used in this study, and the analysis was performed over the aging time of 5000 h. Our findings propose that the Au/HTM/perovskite interface engineering is exclusively essential for attaining a reliable performance of the PSCs and provides a new perspective towards the stability enhancement for the perovskite-based future emerging photovoltaic technology.
Zubair Ahmad; Arti Mishra; Sumayya M. Abdulrahim; D. Taguchi; Paek Sanghyun; Fakhra Aziz; M. Iwamoto; T. Manaka; Jolly Bhadra; Noora J. Al-Thani; Mohammad Khaja Nazeeruddin; Farid Touati; Abdelhak Belaidi; Shaheen A. Al-Muhtaseb. Consequence of aging at Au/HTM/perovskite interface in triple cation 3D and 2D/3D hybrid perovskite solar cells. Scientific Reports 2021, 11, 1 -11.
AMA StyleZubair Ahmad, Arti Mishra, Sumayya M. Abdulrahim, D. Taguchi, Paek Sanghyun, Fakhra Aziz, M. Iwamoto, T. Manaka, Jolly Bhadra, Noora J. Al-Thani, Mohammad Khaja Nazeeruddin, Farid Touati, Abdelhak Belaidi, Shaheen A. Al-Muhtaseb. Consequence of aging at Au/HTM/perovskite interface in triple cation 3D and 2D/3D hybrid perovskite solar cells. Scientific Reports. 2021; 11 (1):1-11.
Chicago/Turabian StyleZubair Ahmad; Arti Mishra; Sumayya M. Abdulrahim; D. Taguchi; Paek Sanghyun; Fakhra Aziz; M. Iwamoto; T. Manaka; Jolly Bhadra; Noora J. Al-Thani; Mohammad Khaja Nazeeruddin; Farid Touati; Abdelhak Belaidi; Shaheen A. Al-Muhtaseb. 2021. "Consequence of aging at Au/HTM/perovskite interface in triple cation 3D and 2D/3D hybrid perovskite solar cells." Scientific Reports 11, no. 1: 1-11.
In this research work, Polydimethylsiloxane (PDMS) has been used for the fabrication of microchannels for biomedical application. Under the internet of things (IoT)-based controlled environment, the authors have simulated and fabricated bio-endurable, biocompatible and bioengineered PDMS-based microchannels for varicose veins implantation exclusively to avoid tissue damaging. Five curved ascending curvilinear micro-channel (5CACMC) and five curved descending curvilinear micro-channels (5CDCMC) are simulated by MATLAB (The Math-Works, Natick, MA, USA) and ANSYS (ANSYS, The University of Lahore, Pakistan) with actual environments and confirmed experimentally. The total length of each channel is 1.6 cm. The diameter of both channels is 400 µm. In the ascending channel, the first to fifth curve cycles have the radii of 2.5 mm, 5 mm, 7.5 mm, 10 mm, and 2.5 mm respectively. In the descending channel, the first and second curve cycles have the radii of 12.5 mm and 10 mm respectively. The third to fifth cycles have the radii of 7.5 mm, 5 mm, and 2.5 mm respectively. For 5CACMC, at Reynolds number of 185, the values of the flow rates, velocities and pressure drops are 19.7 µLs−1, 0.105 mm/s and 1.18 Pa for Fuzzy simulation, 19.3 µLs−1, 0.1543 mm/s and 1.6 Pa for ANSYS simulation and 18.23 µLs−1, 0.1332 mm/s and 1.5 Pa in the experiment. For 5CDCMC, at Reynolds number 143, the values of the flow rates, velocities and pressure drops are 15.4 µLs−1, 0.1032 mm/s and 1.15 Pa for Fuzzy simulation, 15.0 µLs−1, 0.120 mm/s and 1.22 Pa for ANSYS simulation and 14.08 µLs−1, 0.105 mm/s and 1.18 Pa in the experiment. Both channels have three inputs and one output. In order to observe Dean Flow, Dean numbers are also calculated. Therefore, both PDMS channels can be implanted in place of varicose veins to have natural blood flow.
Shahzadi Tayyaba; Muhammad Waseem Ashraf; Zubair Ahmad; Ning Wang; Muhammad Javaid Afzal; Nitin Afzulpurkar. Fabrication and Analysis of Polydimethylsiloxane (PDMS) Microchannels for Biomedical Application. Processes 2020, 9, 57 .
AMA StyleShahzadi Tayyaba, Muhammad Waseem Ashraf, Zubair Ahmad, Ning Wang, Muhammad Javaid Afzal, Nitin Afzulpurkar. Fabrication and Analysis of Polydimethylsiloxane (PDMS) Microchannels for Biomedical Application. Processes. 2020; 9 (1):57.
Chicago/Turabian StyleShahzadi Tayyaba; Muhammad Waseem Ashraf; Zubair Ahmad; Ning Wang; Muhammad Javaid Afzal; Nitin Afzulpurkar. 2020. "Fabrication and Analysis of Polydimethylsiloxane (PDMS) Microchannels for Biomedical Application." Processes 9, no. 1: 57.
Despite the remarkable progress in perovskite solar cells (PSCs), their instability and rapid degradation over time still restrict their commercialization. A 2D capping layer has been proved to overcome the stability issues; however, an in-depth understanding of the complex degradation processes over a prolonged time at PSC interfaces is crucial for improving their stability. In the current work, we investigated the stability of a triple cation 3D ([(FA0.83MA0.17)Cs0.05]Pb(I0.83Br0.17)3) and 2D/3D PSC fabricated by a layer-by-layer deposition technique (PEAI-based 2D layer over triple cation 3D perovskite) using a state-of-art characterization technique: electrochemical impedance spectroscopy (EIS). A long-term stability test over 24 months was performed on the 3D and 2D/3D PSCs with an initial PCE of 18.87% and 20.21%, respectively, to suggest a more practical scenario. The current-voltage (J-V) and EIS results showed degradation in both the solar cell types; however, a slower degradation rate was observed in 2D/3D PSCs. Finally, the quantitative analysis of the key EIS parameters affected by the degradation in 3D and 2D/3D PSCs were discussed.
Sumayya M. Abdulrahim; Zubair Ahmad; Jolly Bhadra; Noora Jabor Al-Thani. Long-Term Stability Analysis of 3D and 2D/3D Hybrid Perovskite Solar Cells Using Electrochemical Impedance Spectroscopy. Molecules 2020, 25, 5794 .
AMA StyleSumayya M. Abdulrahim, Zubair Ahmad, Jolly Bhadra, Noora Jabor Al-Thani. Long-Term Stability Analysis of 3D and 2D/3D Hybrid Perovskite Solar Cells Using Electrochemical Impedance Spectroscopy. Molecules. 2020; 25 (24):5794.
Chicago/Turabian StyleSumayya M. Abdulrahim; Zubair Ahmad; Jolly Bhadra; Noora Jabor Al-Thani. 2020. "Long-Term Stability Analysis of 3D and 2D/3D Hybrid Perovskite Solar Cells Using Electrochemical Impedance Spectroscopy." Molecules 25, no. 24: 5794.
In this research work, we improved the sensing response of the organic-based co-planar humidity sensors using tris(8-hydroxyquinoline) gallium (Gaq3) nanofibers as a dielectric material. The humidity sensor was fabricated by a drop-casting solution in the gap between pre-deposited silver (Ag) electrodes to form Ag/Gaq3/Ag-based capacitive-type humidity sensor. The morphology of the Gaq3 films has been investigated by X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM). At room temperature, the capacitive response of the sensor is evaluated in the range of 0 to 95%RH at 120 Hz & 1 kHz. Notably, at 1 kHz frequency, the sensor shows fast response, good sensitivity, and low hysteresis. The response & recovery times were found to be 6 s each, which are way smaller than those reported in the literature. Such features demonstrate that Gaq3 nanofibers are an up-and-coming candidate for making very sensitive and fast humidity sensors.
Khalil Ur Rehman; Fakhra Aziz; Zubair Ahmad; Khalid Alamgir; Muhammad Asif; Muhammad Tahir; Khaulah Sulaiman; Shahid Bashir; Ehsan Raza; Fahmi F. Muhammadsharif; Jolly Bhadra; Noora J. Al-Thani. Improvement of capacitive humidity sensors using tris(8-hydroxyquinoline) gallium (Gaq3) nanofibers as a dielectric layer. Journal of Materials Science: Materials in Electronics 2020, 31, 21702 -21710.
AMA StyleKhalil Ur Rehman, Fakhra Aziz, Zubair Ahmad, Khalid Alamgir, Muhammad Asif, Muhammad Tahir, Khaulah Sulaiman, Shahid Bashir, Ehsan Raza, Fahmi F. Muhammadsharif, Jolly Bhadra, Noora J. Al-Thani. Improvement of capacitive humidity sensors using tris(8-hydroxyquinoline) gallium (Gaq3) nanofibers as a dielectric layer. Journal of Materials Science: Materials in Electronics. 2020; 31 (23):21702-21710.
Chicago/Turabian StyleKhalil Ur Rehman; Fakhra Aziz; Zubair Ahmad; Khalid Alamgir; Muhammad Asif; Muhammad Tahir; Khaulah Sulaiman; Shahid Bashir; Ehsan Raza; Fahmi F. Muhammadsharif; Jolly Bhadra; Noora J. Al-Thani. 2020. "Improvement of capacitive humidity sensors using tris(8-hydroxyquinoline) gallium (Gaq3) nanofibers as a dielectric layer." Journal of Materials Science: Materials in Electronics 31, no. 23: 21702-21710.
In this work, graphene quantum dots (GQDs) were prepared from Graphitic waste. The resulting GQDs were evaluated for the potential application for resistive humidity sensors. The resistive humidity sensors were fabricated on the pre-patterned interdigital ITO electrodes using the three different concentrations (2.5, 5.0, and 10 mg) of GQDs in DMF. The GQDs films were deposited using the spin coating technique. The GQDs (10 mg/ml) based impedance sensors showed good sensitivity and lowered hysteresis as compared to the other ratios (2.5 and 5 mg) of the GQDs. The maximum calculated hysteresis of the GQDs (10 mg) based humidity sensor is around 2.2 % at 30%RH, and the minimum calculated hysteresis of the GQDs (10 mg/ml) based humidity sensor is approximately 0.79 % at 60 %RH. The response and recovery time found to be 15 s and 55 s, respectively. The interesting humidity-dependent resistive properties of these prepared GQDs make them promising for potential application in humidity sensing.
Khouloud Jlassi; Shoaib Mallick; Abubaker Eribi; Mohamed M. Chehimi; Zubair Ahmad; Farid Touati; Igor Krupa. Facile preparation of N-S co-doped graphene quantum dots (GQDs) from graphite waste for efficient humidity sensing. Sensors and Actuators B: Chemical 2020, 328, 129058 .
AMA StyleKhouloud Jlassi, Shoaib Mallick, Abubaker Eribi, Mohamed M. Chehimi, Zubair Ahmad, Farid Touati, Igor Krupa. Facile preparation of N-S co-doped graphene quantum dots (GQDs) from graphite waste for efficient humidity sensing. Sensors and Actuators B: Chemical. 2020; 328 ():129058.
Chicago/Turabian StyleKhouloud Jlassi; Shoaib Mallick; Abubaker Eribi; Mohamed M. Chehimi; Zubair Ahmad; Farid Touati; Igor Krupa. 2020. "Facile preparation of N-S co-doped graphene quantum dots (GQDs) from graphite waste for efficient humidity sensing." Sensors and Actuators B: Chemical 328, no. : 129058.
Nickel phthalocyanine (NiPc) film was deposited onto the surface of flexible conductive glass by rubbing-in technology and used to fabricate devices based on ITO/NiPc/CNT/Rubber structure. The I-V characteristics of the devices were investigated under different uniaxial pressures of 200, 280 and 480 gf/cm2, applied perpendicular to the surface of the NiPc film. Results showed that the nonlinearity coefficient of the I-V curves are in the range of 2 to 3, which was found to be decreased with the increase of pressure. The rectification ratio of the devices was estimated to be varied from 1.5 to 3 based on the applied pressure. Concluding, the resistance of the active layers was decreased with the increase of both pressure and voltage. We believe that using the rubbingin technology under sufficient applied pressure it is possible to utilize NiPc for the development of various electronic devices such as diodes, non-linear resistors and sensors.
Khasan S. Karimov; Fahmi F. Muhammadsharif; Zubair Ahmad; M. Muqeet Rehman; Rashid Ali. Effect of pressure on the electrical properties of flexible NiPc thin films fabricated by rubbing-in technology. Chinese Physics B 2020, 30, 014703 .
AMA StyleKhasan S. Karimov, Fahmi F. Muhammadsharif, Zubair Ahmad, M. Muqeet Rehman, Rashid Ali. Effect of pressure on the electrical properties of flexible NiPc thin films fabricated by rubbing-in technology. Chinese Physics B. 2020; 30 (1):014703.
Chicago/Turabian StyleKhasan S. Karimov; Fahmi F. Muhammadsharif; Zubair Ahmad; M. Muqeet Rehman; Rashid Ali. 2020. "Effect of pressure on the electrical properties of flexible NiPc thin films fabricated by rubbing-in technology." Chinese Physics B 30, no. 1: 014703.
We have investigated the effect of sulfonated poly (ether ether ketone) (SPEEK) on the thermal stability, hydrophilicity, and sensitivity of polyvinylidene fluoride (PVDF) films based resistive humidity sensors. The blended film was deposited on the pre-patterned interdigited ITO glass electrode by the spin coating technique. The thermal stability of the PVDF-SPEEK composites investigated by thermogravimetric analysis. The surface morphology of the composite blend films has been studied by field emission scanning electron microscopy and atomic force microscopy analyses. The morphology of the PVDF-SPEEK blend films indicates that the PVDF-SPEEK blend is not uniform at high concentrations of SPEEK (over 10 wt%). The hydrophilicity of the sensing film studied by the contact angle method. As the concentration of SPEEK increases in the blend film, the hydrophilicity of the composite film also increases, which enhances the sensitivity of the sensing film. The impedance response of the PVDF-SPEEK blend film shows that the addition of SPEEK enhances the sensitivity of the sensing film at a lower humidity level. Moreover, the response and recovery times of the PVDF-SPEEK (2.5−5 wt%) are found to be 25 s and 65 s, respectively.
Shoaib Mallick; Zubair Ahmad; Abubaker Eribi; Hemalatha Parangusan; Jolly Bahadra; Mohammad K. Hassan; Noora J. Al-Thani; Farid Touati; Shaheen Al-Muhtaseb. Effect of sulfonated poly (ether ether ketone) on the sensitivity of polyvinylidene fluoride-based resistive humidity sensors. Materials Today Communications 2020, 25, 101601 .
AMA StyleShoaib Mallick, Zubair Ahmad, Abubaker Eribi, Hemalatha Parangusan, Jolly Bahadra, Mohammad K. Hassan, Noora J. Al-Thani, Farid Touati, Shaheen Al-Muhtaseb. Effect of sulfonated poly (ether ether ketone) on the sensitivity of polyvinylidene fluoride-based resistive humidity sensors. Materials Today Communications. 2020; 25 ():101601.
Chicago/Turabian StyleShoaib Mallick; Zubair Ahmad; Abubaker Eribi; Hemalatha Parangusan; Jolly Bahadra; Mohammad K. Hassan; Noora J. Al-Thani; Farid Touati; Shaheen Al-Muhtaseb. 2020. "Effect of sulfonated poly (ether ether ketone) on the sensitivity of polyvinylidene fluoride-based resistive humidity sensors." Materials Today Communications 25, no. : 101601.
The future photovoltaic technologies based on perovskite materials are aimed to build low tech, truly economical, easily fabricated, broadly deployable, and trustworthy solar cells. Hole transport material (HTM) free perovskite solar cells (PSCs) are among the most likely architectures which hold a distinctive design and provide a simple way to produce large-area and cost-effective manufacture of PSCs. Notably, in the monolithic scheme of the HTM-free PSCs, all layers can be printed using highly reproducible and morphology-controlled methods, and this design has successfully been demonstrated for industrial-scale fabrication. In this review article, we comprehensively describe the recent advancements in the different types of mesoporous (nanostructured) and planar HTM-free PSCs. In addition, the effect of various nanostructures and mesoporous layers on their performance is discussed using the electrochemical impedance spectroscopy (EIS) technique. We bring together the different perspectives that researchers have developed to interpret and analyze the EIS data of the HTM-free PSCs. Their analysis using the EIS tool, the limitations of these studies, and the future work directions to overcome these limitations to enhance the performance of HTM-free PSCs are comprehensively considered.
Sumayya M. Abdulrahim; Zubair Ahmad; Jolly Bahadra; Noora J. Al-Thani. Electrochemical Impedance Spectroscopy Analysis of Hole Transporting Material Free Mesoporous and Planar Perovskite Solar Cells. Nanomaterials 2020, 10, 1635 .
AMA StyleSumayya M. Abdulrahim, Zubair Ahmad, Jolly Bahadra, Noora J. Al-Thani. Electrochemical Impedance Spectroscopy Analysis of Hole Transporting Material Free Mesoporous and Planar Perovskite Solar Cells. Nanomaterials. 2020; 10 (9):1635.
Chicago/Turabian StyleSumayya M. Abdulrahim; Zubair Ahmad; Jolly Bahadra; Noora J. Al-Thani. 2020. "Electrochemical Impedance Spectroscopy Analysis of Hole Transporting Material Free Mesoporous and Planar Perovskite Solar Cells." Nanomaterials 10, no. 9: 1635.
Background: The photo-absorption and light trapping through the different layers of the organic solar cell structures are a growing concern now-a-days as it affects dramatically the overall efficiency of the cells. In fact, selecting the right material combination is a key factor in increasing the efficiency in the layers. In addition to good absorption properties, insertion of nanostructures has been proved in recent researches to affect significantly the light trapping inside the organic solar cell. All these factors are determined to expand the absorption spectrum and tailor it to a wider spectrum. Objective: The purpose of this investigation is to explore the consequence of the incorporation of the Ag nanostructures, with different sizes and structures, on the photo absorption of the organic BHJ thin films. Methods: Through a three-dimensional Maxwell solver software, Lumerical FDTD, a simulation and comparison of the optical absorption of the three famous organic materials blends poly(3- hexylthiophene): phenyl C71 butyric acid methyl ester (P3HT:PCBM), poly[N-9″-heptadecanyl-2,7- carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)]: phenyl C71 butyric acid methyl ester (PCDTBT:PCBM) and poly[2,6-(4,4-bis-(2-ethylhexyl)-4H-cyclopenta[2,1-b;3,4-b′]dithiophene)-alt- 4,7-(2,1,3-benzothiadiazole)]: phenyl C71 butyric acid methyl ester (PCDPDTBT:PCBM) has been conducted. Furthermore, FDTD simulation study of the incorporation of nanoparticles structures with different sizes, in different locations and concentrations through a bulk heterojunction organic solar cell structure has also been performed. Results: It has been demonstrated that embedding nanostructures in different locations of the cell, specifically in the active layer and the hole transporting layer had a considerable effect of widening the absorption spectrum and increasing the short circuit current. The effect of incorporation the nanostructures in the active layer has been proved to be greater than in the HTL. Furthermore, the comparison results showed that, PCDTBT:PCBM is no more advantageous over P3HT:PCBM and PCPDTBT:PCBM, and P3HT:PCBM took the lead and showed better performance in terms of absorption spectrum and short circuit current value. Conclusion: This work revealed the significant effect of size, location and concentration of the Ag nanostructures while incorporated in the organic solar cell. In fact, embedding nanostructures in the solar cell widen the absorption spectrum and increases the short circuit current, this result has been proven to be significant only when the nanostructures are inserted in the active layer following specific dimensions and structures.
Asma Khalil; Zubair Ahmad; Farid Touati; Mohamed Masmoudi. Optical Absorption Enhancement in Polymer BHJ thin Film Using Ag Nanostructures: A Simulation Study. Current Nanoscience 2020, 16, 556 -567.
AMA StyleAsma Khalil, Zubair Ahmad, Farid Touati, Mohamed Masmoudi. Optical Absorption Enhancement in Polymer BHJ thin Film Using Ag Nanostructures: A Simulation Study. Current Nanoscience. 2020; 16 (4):556-567.
Chicago/Turabian StyleAsma Khalil; Zubair Ahmad; Farid Touati; Mohamed Masmoudi. 2020. "Optical Absorption Enhancement in Polymer BHJ thin Film Using Ag Nanostructures: A Simulation Study." Current Nanoscience 16, no. 4: 556-567.
Halloysite-polypyrrole-silver nanocomposite has been prepared via in situ photopolymerizations of pyrrole in the presence of silanized halloysite and silver nitrate as a photoinitiator. The halloysite nanoclay (HNT) was modified using the hydrogen donor silane coupling agent (DMA) in order to provide anchoring sites for the polypyrrole/silver composite ([email protected]). The mass loadings for both PPy and Ag have been estimated to be 21 and 26 wt%, respectively. The anchored Ag particles were found in the metallic state. The resulting [email protected] silanized HNT has been evaluated for the potential application for impedance humidity sensors. [email protected] nanocomposite with different weight % of [email protected] (0.25 wt%, 0.5 wt%, and 1 wt%) was deposited on the pre-patterned interdigital Indium Tin Oxide (ITO) electrodes by spin coating technique. The addition of Ag nanoparticles within the nanocomposite enhances the hydrophilicity of the sensing film, which improves the sensitivity of the humidity sensors. The [email protected] (0.5 wt%) nanocomposite-based impedance sensors showed good sensitivity and lowered hysteresis as compared to the other ratios of the composite. The maximum calculated hysteresis loss of the [email protected] (0.5 wt%)-based humidity sensor is around 4.5% at 80% RH (relative humidity), and the minimum hysteresis loss estimated to be 0.05% at 20% RH levels. The response and recovery time of [email protected] (0.5 wt%) nanocomposite-based impedance sensors were found to be 30 and 35 s, respectively. The interesting humidity-dependent impedance properties of this novel composite make it promising in humidity sensing.
Khouloud Jlassi; Shoaib Mallick; Hafsa Mutahir; Zubair Ahmad; Farid Touati. Synthesis of In Situ Photoinduced [email protected] Nanocomposite for the Potential Application in Humidity Sensors. Nanomaterials 2020, 10, 1426 .
AMA StyleKhouloud Jlassi, Shoaib Mallick, Hafsa Mutahir, Zubair Ahmad, Farid Touati. Synthesis of In Situ Photoinduced [email protected] Nanocomposite for the Potential Application in Humidity Sensors. Nanomaterials. 2020; 10 (7):1426.
Chicago/Turabian StyleKhouloud Jlassi; Shoaib Mallick; Hafsa Mutahir; Zubair Ahmad; Farid Touati. 2020. "Synthesis of In Situ Photoinduced [email protected] Nanocomposite for the Potential Application in Humidity Sensors." Nanomaterials 10, no. 7: 1426.
The expedient way for the development of microelectromechanical systems (MEMS) based devices are based on two key steps. First, perform the simulation for the optimization of various parameters by using different simulation tools that lead to cost reduction. Second, develop the devices with accurate fabrication steps using optimized parameters. Here, authors have performed a piezoelectric analysis of an array of zinc oxide (ZnO) nanostructures that have been created on both sides of aluminum sheets. Various quantities like swerve, stress, strain, electric flux, energy distribution, and electric potential have been studied during the piezo analysis. Then actual controlled growth of ZnO nanorods (NRs) arrays was done on both sides of the etched aluminum rod at low-temperature using the chemical bath deposition (CBD) method for the development of a MEMS energy harvester. Micro creaks on the substrate acted as an alternative to the seed layer. The testing was performed by applying ambient range force on the nanostructure. It was found that the voltage range on topside was 0.59 to 0.62 mV, and the bottom side was 0.52 to 0.55 mV. These kinds of devices are useful in low power micro-devices, nanoelectromechanical systems, and smart wearable systems.
Muhammad Wasim; Shahzadi Tayyaba; Muhammad Ashraf; Zubair Ahmad. Modeling and Piezoelectric Analysis of Nano Energy Harvesters. Sensors 2020, 20, 3931 .
AMA StyleMuhammad Wasim, Shahzadi Tayyaba, Muhammad Ashraf, Zubair Ahmad. Modeling and Piezoelectric Analysis of Nano Energy Harvesters. Sensors. 2020; 20 (14):3931.
Chicago/Turabian StyleMuhammad Wasim; Shahzadi Tayyaba; Muhammad Ashraf; Zubair Ahmad. 2020. "Modeling and Piezoelectric Analysis of Nano Energy Harvesters." Sensors 20, no. 14: 3931.
Polyaniline (PANI)/Cu–ZnS composites with porous microspheres are prepared by a hydrothermal and in situ polymerization method.
Hemalatha Parangusan; Jolly Bhadra; Zubair Ahmad; Shoaib Mallick; Farid Touati; Noora Al-Thani. Investigation of the structural, optical and gas sensing properties of PANI coated Cu–ZnS microsphere composite. RSC Advances 2020, 10, 26604 -26612.
AMA StyleHemalatha Parangusan, Jolly Bhadra, Zubair Ahmad, Shoaib Mallick, Farid Touati, Noora Al-Thani. Investigation of the structural, optical and gas sensing properties of PANI coated Cu–ZnS microsphere composite. RSC Advances. 2020; 10 (45):26604-26612.
Chicago/Turabian StyleHemalatha Parangusan; Jolly Bhadra; Zubair Ahmad; Shoaib Mallick; Farid Touati; Noora Al-Thani. 2020. "Investigation of the structural, optical and gas sensing properties of PANI coated Cu–ZnS microsphere composite." RSC Advances 10, no. 45: 26604-26612.
Recently, the 2D perovskite layer is employed as a capping/passivating layer in the perovskite solar cells (PSCs). The 2D perovskite layer is prepared by inserting a large-sized hydrophobic cation spacer into the perovskite crystal lattice. The large-sized cation in the 2D perovskite lattice can successfully suppress the moisture intrusion and hence improve the stability of the PSCs. However, a deep understanding of the interfacial mechanisms at the 2D/3D heterojunction and the relative contributions of the mobile ions and trapped charge carriers is still lacking. In this work, deep levels transient spectroscopy (DLTS) and reverse DLTS (RDLTS) have been performed to characterize the n-i-p structured 3D and 2D/3D PSCs. DLTS and RDLTS have been used to distinguish between the spectral contribution made by mobile ionic species, electron/hole traps, and to investigate the presence of ordinary deep electron and hole traps in the bandgap of perovskite. Besides, the PSCs have been characterized by photoinduced voltage transient spectroscopy (PIVTS) to study the decay of the open-circuit voltage (VOC) under illumination. For both 3D and 2D/3D PSCs, the contribution of mobile ions was found to be dominant; however, in the case of 2D/3D samples, the intensity of the mobile ions signal was several times lower. The lower intensity can be correlated with a lower amplitude of slow tails in VOC decay curves in 2D/3D solar cells as compared to 3D solar cells. The PIVTS study also endorses the 2D/3D structures as more robust than the 3D structures.
Ali Sehpar Shikoh; Sanghyun Paek; Alexander Y. Polyakov; Nikolai B. Smirnov; Ivan V. Shchemerov; Danila S. Saranin; Sergey I. Didenko; Zubair Ahmad; Farid Touati; Mohammad Khaja Nazeeruddin. Assessing mobile ions contributions to admittance spectra and current-voltage characteristics of 3D and 2D/3D perovskite solar cells. Solar Energy Materials and Solar Cells 2020, 215, 110670 .
AMA StyleAli Sehpar Shikoh, Sanghyun Paek, Alexander Y. Polyakov, Nikolai B. Smirnov, Ivan V. Shchemerov, Danila S. Saranin, Sergey I. Didenko, Zubair Ahmad, Farid Touati, Mohammad Khaja Nazeeruddin. Assessing mobile ions contributions to admittance spectra and current-voltage characteristics of 3D and 2D/3D perovskite solar cells. Solar Energy Materials and Solar Cells. 2020; 215 ():110670.
Chicago/Turabian StyleAli Sehpar Shikoh; Sanghyun Paek; Alexander Y. Polyakov; Nikolai B. Smirnov; Ivan V. Shchemerov; Danila S. Saranin; Sergey I. Didenko; Zubair Ahmad; Farid Touati; Mohammad Khaja Nazeeruddin. 2020. "Assessing mobile ions contributions to admittance spectra and current-voltage characteristics of 3D and 2D/3D perovskite solar cells." Solar Energy Materials and Solar Cells 215, no. : 110670.
The demand of devices for safe mobility of blind people is increasing with advancement in wireless communication. Artificial intelligent devices with multiple input and output methods are used for reliable data estimation based on maximum probability. A model of a smart home for safe and robust mobility of blind people has been proposed. Fuzzy logic has been used for simulation. Outputs from the internet of things (IoT) devices comprising sensors and bluetooth are taken as input of the fuzzy controller. Rules have been developed based on the conditions and requirements of the blind person to generate decisions as output. These outputs are communicated through IoT devices to assist the blind person or user for safe movement. The proposed system provides the user with easy navigation and obstacle avoidance.
Shahzadi Tayyaba; Muhammad Waseem Ashraf; Thamer Alquthami; Zubair Ahmad; Saher Manzoor. Fuzzy-Based Approach Using IoT Devices for Smart Home to Assist Blind People for Navigation. Sensors 2020, 20, 3674 .
AMA StyleShahzadi Tayyaba, Muhammad Waseem Ashraf, Thamer Alquthami, Zubair Ahmad, Saher Manzoor. Fuzzy-Based Approach Using IoT Devices for Smart Home to Assist Blind People for Navigation. Sensors. 2020; 20 (13):3674.
Chicago/Turabian StyleShahzadi Tayyaba; Muhammad Waseem Ashraf; Thamer Alquthami; Zubair Ahmad; Saher Manzoor. 2020. "Fuzzy-Based Approach Using IoT Devices for Smart Home to Assist Blind People for Navigation." Sensors 20, no. 13: 3674.