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Dr. Seyed Ahmad Shahahmadi
Post Doctoral Researcher

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0 Solar Cells
0 lasers
0 Thin Film Deposition
0 Material Science
0 Epitaxial growth

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Interested in the optoelectronic characterization of semiconductors, solar cells, and lasers by experimental and numerical modeling techniques.

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Review
Published: 18 June 2021 in Sustainability
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The reliability of photovoltaic (PV) modules operating under various weather conditions attracts the manufacturer’s concern since several studies reveal a degradation rate higher than 0.8% per year for the silicon-based technology and reached up to 2.76% per year in a harsh climate. The lifetime of the PV modules is decreased because of numerous degradation modes. Electromigration and delamination are two failure modes that play a significant role in PV modules’ output power losses. The correlations of these two phenomena are not sufficiently explained and understood like other failures such as corrosion and potential-induced degradation. Therefore, in this review, we attempt to elaborate on the correlation and the influence of delamination and electromigration on PV module components such as metallization and organic materials to ensure the reliability of the PV modules. Moreover, the effects, causes, and the sites that tend to face these failures, particularly the silicon solar cells, are explained in detail. Elsewhere, the factors of aging vary as the temperature and humidity change from one country to another. Hence, accelerated tests and the standards used to perform the aging test for PV modules have been covered in this review.

ACS Style

Abdulwahab Hasan; Ammar Ahmed Alkahtani; Seyed Shahahmadi; Mohammad Nur E. Alam; Mohammad Islam; Nowshad Amin. Delamination-and Electromigration-Related Failures in Solar Panels—A Review. Sustainability 2021, 13, 6882 .

AMA Style

Abdulwahab Hasan, Ammar Ahmed Alkahtani, Seyed Shahahmadi, Mohammad Nur E. Alam, Mohammad Islam, Nowshad Amin. Delamination-and Electromigration-Related Failures in Solar Panels—A Review. Sustainability. 2021; 13 (12):6882.

Chicago/Turabian Style

Abdulwahab Hasan; Ammar Ahmed Alkahtani; Seyed Shahahmadi; Mohammad Nur E. Alam; Mohammad Islam; Nowshad Amin. 2021. "Delamination-and Electromigration-Related Failures in Solar Panels—A Review." Sustainability 13, no. 12: 6882.

Journal article
Published: 06 January 2021 in Coatings
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A CdS thin film buffer layer has been widely used as conventional n-type heterojunction partner both in established and emerging thin film photovoltaic devices. In this study, we perform numerical simulation to elucidate the influence of electrical properties of the CdS buffer layer, essentially in terms of carrier mobility and carrier concentration on the performance of SLG/Mo/p-Absorber/n-CdS/n-ZnO/Ag configured thin film photovoltaic devices, by using the Solar Cell Capacitance Simulator (SCAPS-1D). A wide range of p-type absorber layers with a band gap from 0.9 to 1.7 eV and electron affinity from 3.7 to 4.7 eV have been considered in this simulation study. For an ideal absorber layer (no defect), the carrier mobility and carrier concentration of CdS buffer layer do not significantly alter the maximum attainable efficiency. Generally, it was revealed that for an absorber layer with a conduction band offset (CBO) that is more than 0.3 eV, Jsc is strongly dependent on the carrier mobility and carrier concentration of the CdS buffer layer, whereas Voc is predominantly dependent on the back contact barrier height. However, as the bulk defect density of the absorber layer is increased from 1014 to 1018 cm−3, a CdS buffer layer with higher carrier mobility and carrier concentration is an imperative requirement to a yield device with higher conversion efficiency and a larger band gap-CBO window for realization of a functional device. Most tellingly, simulation outcomes from this study reveal that electrical properties of the CdS buffer layer play a decisive role in determining the progress of emerging p-type photo-absorber layer materials, particularly during the embryonic device development stage.

ACS Style

Asmaa Soheil Najm; Puvaneswaran Chelvanathan; Sieh Kiong Tiong; Mohammad Tanvirul Ferdaous; Seyed Ahmad Shahahmadi; Yulisa Yusoff; Kamaruzzaman Sopian; Nowshad Amin. Numerical Insights into the Influence of Electrical Properties of n-CdS Buffer Layer on the Performance of SLG/Mo/p-Absorber/n-CdS/n-ZnO/Ag Configured Thin Film Photovoltaic Devices. Coatings 2021, 11, 52 .

AMA Style

Asmaa Soheil Najm, Puvaneswaran Chelvanathan, Sieh Kiong Tiong, Mohammad Tanvirul Ferdaous, Seyed Ahmad Shahahmadi, Yulisa Yusoff, Kamaruzzaman Sopian, Nowshad Amin. Numerical Insights into the Influence of Electrical Properties of n-CdS Buffer Layer on the Performance of SLG/Mo/p-Absorber/n-CdS/n-ZnO/Ag Configured Thin Film Photovoltaic Devices. Coatings. 2021; 11 (1):52.

Chicago/Turabian Style

Asmaa Soheil Najm; Puvaneswaran Chelvanathan; Sieh Kiong Tiong; Mohammad Tanvirul Ferdaous; Seyed Ahmad Shahahmadi; Yulisa Yusoff; Kamaruzzaman Sopian; Nowshad Amin. 2021. "Numerical Insights into the Influence of Electrical Properties of n-CdS Buffer Layer on the Performance of SLG/Mo/p-Absorber/n-CdS/n-ZnO/Ag Configured Thin Film Photovoltaic Devices." Coatings 11, no. 1: 52.

Journal article
Published: 23 April 2020 in Ceramics International
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Chemical bath deposition (CBD) method was used to deposit CdS thin films on soda-lime glass substrates by using n-methylthiourea (NTU) as an alternative sulphur source and are compared with typical thiourea (TU) precursor. The sulphur source concentration was varied from 0.01 M to 0.1 M and the impact on the microstructural, surface morphology, optical and electrical properties of the grown films were studied. Increasing n-methylthiourea concentration in the precursor yields in thinner films that are less than 100 nm thickness, surface morphology with slightly higher average surface roughness of 6.4 nm, larger granular structure, wider band gap at 2.3 eV–2.6 eV range and a Raman spectroscopy reveals Raman peak at 303 cm-1. In contrast, an increase in thiourea concentration results in thinner film, amorphous, less distinct granular structure, narrow energy band gap from 2.3 eV to 2.4 eV and a resonance Raman peak at 302 cm-1. CdS thin film deposited from n-methylthiourea precursor showed better electrical properties such as lower resistivity and higher carrier mobility compared to the thin film deposited from typical thiourea precursor.

ACS Style

N. Azmi; P. Chelvanathan; Y. Yusoff; Seyed Ahmad Shahahmadi; S.K. Tiong; K. Sopian; N. Amin. A comprehensive study on the effects of alternative sulphur precursor on the material properties of chemical bath deposited CdS thin films. Ceramics International 2020, 46, 18716 -18724.

AMA Style

N. Azmi, P. Chelvanathan, Y. Yusoff, Seyed Ahmad Shahahmadi, S.K. Tiong, K. Sopian, N. Amin. A comprehensive study on the effects of alternative sulphur precursor on the material properties of chemical bath deposited CdS thin films. Ceramics International. 2020; 46 (11):18716-18724.

Chicago/Turabian Style

N. Azmi; P. Chelvanathan; Y. Yusoff; Seyed Ahmad Shahahmadi; S.K. Tiong; K. Sopian; N. Amin. 2020. "A comprehensive study on the effects of alternative sulphur precursor on the material properties of chemical bath deposited CdS thin films." Ceramics International 46, no. 11: 18716-18724.

Journal article
Published: 01 March 2020 in Results in Physics
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ACS Style

M.S. Chowdhury; S.A. Shahahmadi; P. Chelvanathan; S.K. Tiong; N. Amin; K. Techato; N. Nuthammachot; T. Chowdhury; M. Suklueng. Effect of deep-level defect density of the absorber layer and n/i interface in perovskite solar cells by SCAPS-1D. Results in Physics 2020, 16, 1 .

AMA Style

M.S. Chowdhury, S.A. Shahahmadi, P. Chelvanathan, S.K. Tiong, N. Amin, K. Techato, N. Nuthammachot, T. Chowdhury, M. Suklueng. Effect of deep-level defect density of the absorber layer and n/i interface in perovskite solar cells by SCAPS-1D. Results in Physics. 2020; 16 ():1.

Chicago/Turabian Style

M.S. Chowdhury; S.A. Shahahmadi; P. Chelvanathan; S.K. Tiong; N. Amin; K. Techato; N. Nuthammachot; T. Chowdhury; M. Suklueng. 2020. "Effect of deep-level defect density of the absorber layer and n/i interface in perovskite solar cells by SCAPS-1D." Results in Physics 16, no. : 1.

Journal article
Published: 24 May 2019 in Results in Physics
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In this study, nickel oxide (NiO) thin films were deposited on soda lime glass using radio-frequency magnetron sputtering at different growth (substrate) temperatures ranging from room temperature (RT) to 400 °C. The effects of substrate temperature on the structural, morphological, electrical, and optical properties were investigated. The XRD pattern unveiled a dominant peak with (2 0 0) preferential orientations for the film grown at 100 °C. However, for samples grown at high temperatures, a gradual decrease of (2 0 0) peak intensity was observed, which may be the result of the decomposition of NiO as confirmed via EDX. Surface morphology from FESEM revealed that grains were randomly orientated on the surface with maximum grain size of 19.43 nm. Upon increasing the growth temperature, the crystal quality and grain size substantially deteriorated, which is consistent with the XRD results. Scanning probe microscopy (SPM) finds rough surface with the highest surface roughness obtained at RT with a value of 1.232 nm. Electrical resistivity was found to be highly dependent on the growth temperature that decreases from 2150 Ω cm to 72 Ω cm as the substrate temperature increases. For optical properties, the optical bandgap of the NiO films decreases from 3.8 eV to 3.2 eV as a function of substrate temperature as derived from the optical transmittance data. Results show the potential application of the NiO films in photovoltaic devices.

ACS Style

M.S Jamal; S.A. Shahahmadi; P. Chelvanathan; Hamad F. Alharbi; Mohammad R. Karim; Mushtaq Ahmad Dar; Monis Luqman; Nabeel H. Alharthi; Yahya S. Al-Harthi; M. Aminuzzaman; Nilofar Asim; K. Sopian; S.K. Tiong; Nowshad Amin; Akhtaruzzaman. Effects of growth temperature on the photovoltaic properties of RF sputtered undoped NiO thin films. Results in Physics 2019, 14, 102360 .

AMA Style

M.S Jamal, S.A. Shahahmadi, P. Chelvanathan, Hamad F. Alharbi, Mohammad R. Karim, Mushtaq Ahmad Dar, Monis Luqman, Nabeel H. Alharthi, Yahya S. Al-Harthi, M. Aminuzzaman, Nilofar Asim, K. Sopian, S.K. Tiong, Nowshad Amin, Akhtaruzzaman. Effects of growth temperature on the photovoltaic properties of RF sputtered undoped NiO thin films. Results in Physics. 2019; 14 ():102360.

Chicago/Turabian Style

M.S Jamal; S.A. Shahahmadi; P. Chelvanathan; Hamad F. Alharbi; Mohammad R. Karim; Mushtaq Ahmad Dar; Monis Luqman; Nabeel H. Alharthi; Yahya S. Al-Harthi; M. Aminuzzaman; Nilofar Asim; K. Sopian; S.K. Tiong; Nowshad Amin; Akhtaruzzaman. 2019. "Effects of growth temperature on the photovoltaic properties of RF sputtered undoped NiO thin films." Results in Physics 14, no. : 102360.

Journal article
Published: 28 December 2018 in Optik
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The defects at the absorber and interface layer of organic-inorganic lead halide perovskite solar cells are unfavorable for efficiency as well as the stability. In this study, we have performed the numerical simulation on inverted planar structure perovskite solar cell based on NiO as a hole transport material (HTM) by SCAPS-1D. Here we investigated the effects of defect density and energy level of the perovskite absorber layer and perovskite/HTM interface layer on the performance, respectively. The analysis revealed that values of Jsc, Voc, and FF of perovskite solar cells are significantly reduced with increasing the defect density of perovskite layer. The power conversion efficiency severely reduced from 25 to 5% when the defect density increased from 1013 to 1018 cm−3, respectively. A similar trend was also found in case of interfacial defect between Perovskite and HTM layer. It was found that the defect energy level more than 0.3 eV above conduction band of perovskite has almost no detrimental effect on the device’s efficiency.

ACS Style

M.S. Jamal; S.A. Shahahmadi; Mohd. Aizat Abdul Wadi; P. Chelvanathan; N. Asim; H. Misran; M.I. Hossain; N. Amin; Kamaruzzaman Sopian; Akhtaruzzaman. Effect of defect density and energy level mismatch on the performance of perovskite solar cells by numerical simulation. Optik 2018, 182, 1204 -1210.

AMA Style

M.S. Jamal, S.A. Shahahmadi, Mohd. Aizat Abdul Wadi, P. Chelvanathan, N. Asim, H. Misran, M.I. Hossain, N. Amin, Kamaruzzaman Sopian, Akhtaruzzaman. Effect of defect density and energy level mismatch on the performance of perovskite solar cells by numerical simulation. Optik. 2018; 182 ():1204-1210.

Chicago/Turabian Style

M.S. Jamal; S.A. Shahahmadi; Mohd. Aizat Abdul Wadi; P. Chelvanathan; N. Asim; H. Misran; M.I. Hossain; N. Amin; Kamaruzzaman Sopian; Akhtaruzzaman. 2018. "Effect of defect density and energy level mismatch on the performance of perovskite solar cells by numerical simulation." Optik 182, no. : 1204-1210.

Journal article
Published: 19 December 2018 in Solar Energy
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In this study, the effects of transition metal dichalcogenide, MoS2 interfacial layer formation between the Cu2ZnSnS4 (CZTS) absorber layer and Mo back contact in a conventional CZTS thin film solar cell (TFSC) structure have been studied by numerical simulation using wxAMPS-1D software. The goal of this study is to elucidate the effects of both n and p-type MoS2 on the overall CZTS solar cell’s performance from the viewpoint of metal-semiconductor junction and heterojunction band alignment. Interestingly, CZTS device, regardless of p or n-type MoS2 largely outperforms device without any MoS2 due to lower back contact barrier value. Significant transition in efficiency is noticed when acceptor (increases efficiency) or donor (decreases efficiency) concentration has a transition from 1016 cm−3 to higher concentration of 1018 cm−3 or more. Also, effect of variable electron affinity and band gap of MoS2 has been discussed from band alignment perspective. Generally, MoS2 layer with lower electron affinity and band gap is preferred to induce desirable band alignment and subsequently result in higher efficiency. All-in all, the formation of p-type MoS2 in CZTS solar cells can be tuned to improve the cell performance mainly by doping with higher acceptor doping concentration and limiting layer thickness. However, the detrimental effect of n-MoS2 can be prevented by maintaining thinner layer in the vicinity of ∼30 nm with low to moderate donor doping (<1016 cm−3).

ACS Style

M.T. Ferdaous; S.A. Shahahmadi; P. Chelvanathan; Akhtaruzzaman; F.H. Alharbi; Kamaruzzaman Sopian; S.K. Tiong; Nowshad Amin. Elucidating the role of interfacial MoS2 layer in Cu2ZnSnS4 thin film solar cells by numerical analysis. Solar Energy 2018, 178, 162 -172.

AMA Style

M.T. Ferdaous, S.A. Shahahmadi, P. Chelvanathan, Akhtaruzzaman, F.H. Alharbi, Kamaruzzaman Sopian, S.K. Tiong, Nowshad Amin. Elucidating the role of interfacial MoS2 layer in Cu2ZnSnS4 thin film solar cells by numerical analysis. Solar Energy. 2018; 178 ():162-172.

Chicago/Turabian Style

M.T. Ferdaous; S.A. Shahahmadi; P. Chelvanathan; Akhtaruzzaman; F.H. Alharbi; Kamaruzzaman Sopian; S.K. Tiong; Nowshad Amin. 2018. "Elucidating the role of interfacial MoS2 layer in Cu2ZnSnS4 thin film solar cells by numerical analysis." Solar Energy 178, no. : 162-172.

Journal article
Published: 15 November 2018 in Solar Energy
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In this present work, we report a novel fabrication technique of ternary Cu2SnS3 (CTS) thin films by sulphurization of sequentially sputtered Sn/CuSn (elemental/alloy) stacked metallic precursors. The focal aim of our investigation is on the impact of metallic precursors’ Cu/Sn ratio on the overall material properties of CTS films, which in turn, influence the photovoltaic device performance. All CTSs exhibited polycrystalline films with a mixture monoclinic CTS and orthorhombic SnS compound, p-type conductivity, and optical band gap in the range of 0.84–0.90 eV. Metallic precursor with Cu/Sn ratio of 1.09 produced optimum CTS film with post-sulphurization Cu/Sn ratio of 1.98 and highest conversion efficiency of 0.71%, respectively, despite exhibiting pronounced formation of SnS secondary phase. The correlation between XRD, Raman, and SEM-EDX outcomes revealed that CTS films from metallic precursors with Cu/Sn ratio higher than 1.09 undergo severe microstructural degradation due to Sn-loss through decomposition of volatile SnS phase and consequently, resulted in poorer absorber layer quality and lower device performance. Finally, several efficiency impeding factors are discussed and practical propostions to overcome them are presented.

ACS Style

Ejarder Sabbir Hossain; Puvaneswaran Chelvanathan; Seyed Ahmad Shahahmadi; Badariah Bais; Akhtaruzzaman; Sieh Kiong Tiong; Kamaruzzaman Sopian; Nowshad Amin. Fabrication of Cu2SnS3 thin film solar cells by sulphurization of sequentially sputtered Sn/CuSn metallic stacked precursors. Solar Energy 2018, 177, 262 -273.

AMA Style

Ejarder Sabbir Hossain, Puvaneswaran Chelvanathan, Seyed Ahmad Shahahmadi, Badariah Bais, Akhtaruzzaman, Sieh Kiong Tiong, Kamaruzzaman Sopian, Nowshad Amin. Fabrication of Cu2SnS3 thin film solar cells by sulphurization of sequentially sputtered Sn/CuSn metallic stacked precursors. Solar Energy. 2018; 177 ():262-273.

Chicago/Turabian Style

Ejarder Sabbir Hossain; Puvaneswaran Chelvanathan; Seyed Ahmad Shahahmadi; Badariah Bais; Akhtaruzzaman; Sieh Kiong Tiong; Kamaruzzaman Sopian; Nowshad Amin. 2018. "Fabrication of Cu2SnS3 thin film solar cells by sulphurization of sequentially sputtered Sn/CuSn metallic stacked precursors." Solar Energy 177, no. : 262-273.

Journal article
Published: 01 October 2018 in Optik
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Ta2O5 thin films, proposed as the replacement of the precious Pt based electro-catalyst in fuel cells, were sputtered on laser textured silicon substrate at 200 °C and then air annealed at 350 °C, 400 °C and 450 °C with the aim to improve crystallinity and uniformity. Characterization such as FESEM, XRD, Hall effect and Cyclic Voltammetry were employed to investigate the morphological, structural, electrical and electrochemical properties of the as-sputtered as well as annealed samples. Initial results showed that the films obtained by increasing the substrate temperature during sputtering are smoother and have better adhesion to the etched silicon substrates. It has also been observed that the rate of deposition increases resulting in thicker films for longer deposition time at higher temperature. Upon annealing, Ta2O5 films achieved better crystallinity consisting of orthorhombic phases. The average thicknesses of the films are in the range of 400 nm to 700 nm. The proposed catalyst also shows better enhancement for oxygen reduction reaction (ORR) in prolonged time of continuous potentiostatic electrolysis as to be used in fuel cells.

ACS Style

N. Samsudin; M.T. Ferdaous; S.A. Shahahmadi; S.N. Mustafa; Akhtaruzzaman; K. Sopian; P. Chelvanathan; Nowshad Amin. Deposition and characterization of RF-sputtered-Ta2O5 thin films for O2 reduction reaction in polymer electrolyte membrane fuel cells (PEMFC). Optik 2018, 170, 295 -303.

AMA Style

N. Samsudin, M.T. Ferdaous, S.A. Shahahmadi, S.N. Mustafa, Akhtaruzzaman, K. Sopian, P. Chelvanathan, Nowshad Amin. Deposition and characterization of RF-sputtered-Ta2O5 thin films for O2 reduction reaction in polymer electrolyte membrane fuel cells (PEMFC). Optik. 2018; 170 ():295-303.

Chicago/Turabian Style

N. Samsudin; M.T. Ferdaous; S.A. Shahahmadi; S.N. Mustafa; Akhtaruzzaman; K. Sopian; P. Chelvanathan; Nowshad Amin. 2018. "Deposition and characterization of RF-sputtered-Ta2O5 thin films for O2 reduction reaction in polymer electrolyte membrane fuel cells (PEMFC)." Optik 170, no. : 295-303.

Review
Published: 15 August 2018 in Energy Conversion and Management
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Thermoelectric technology is a promising solution to recover waste heat from different resources. There are numerous researches in the literature that measure performance of thermoelectric modules (TEMs). A comprehensive review of research studies that classifies and expounds disparities between various thermoelectric power generation (TEPG) systems is still unavailable and therefore, this paper reviews major concerns on their designs and performances. Firstly, various main elements of TEPG systems, which affect the output power of TEMs such as stabilizer or heat exchanger, interface, contact pressure, insulation, cooling system, and integrity are studied. Secondly, performances of test rigs and various prototypes are reviewed in detail based on their cooling methods since cooling is the most prominent factor among other counterparts. In general, the cooling unit is divided into either passive or active cooling system, which is selected based on its well-defined use. A comprehensive study on various test rigs with active cooling systems is given while a broader range in prototypes is covered and classified under detailed surveys. This review is expected to be of value for researchers in the field of thermoelectric. Overall, in order to have a prospective future towards commercialization of TEPG systems, the existing prototypes in the literature are still subjected to many enhancements in their design aspects, while further improvements are needed to be achieved independently in TEMs’ development.

ACS Style

Mohammad Alghoul; S.A. Shahahmadi; Bita Yeganeh; Nilofar Asim; A.M Elbreki; Kamaruzzaman Sopian; S.K. Tiong; Nowshad Amin. A review of thermoelectric power generation systems: Roles of existing test rigs/ prototypes and their associated cooling units on output performance. Energy Conversion and Management 2018, 174, 138 -156.

AMA Style

Mohammad Alghoul, S.A. Shahahmadi, Bita Yeganeh, Nilofar Asim, A.M Elbreki, Kamaruzzaman Sopian, S.K. Tiong, Nowshad Amin. A review of thermoelectric power generation systems: Roles of existing test rigs/ prototypes and their associated cooling units on output performance. Energy Conversion and Management. 2018; 174 ():138-156.

Chicago/Turabian Style

Mohammad Alghoul; S.A. Shahahmadi; Bita Yeganeh; Nilofar Asim; A.M Elbreki; Kamaruzzaman Sopian; S.K. Tiong; Nowshad Amin. 2018. "A review of thermoelectric power generation systems: Roles of existing test rigs/ prototypes and their associated cooling units on output performance." Energy Conversion and Management 174, no. : 138-156.

Journal article
Published: 01 August 2018 in Thin Solid Films
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Gallium-doped zinc oxide (GZO) is a potential transparent conductive oxide material suitable for modern photovoltaics among other applications. In this study, GZO thin films were deposited by a confocal direct current sputtering system to investigate effects of various deposition parameters such as power (60 and 100 W), substrate temperature (50, 100, 150 and 200 °C) and sample location (3 spots) on optoelectronic properties of GZO films. In this regard, X-ray diffraction, ultraviolet-visible-infrared spectroscopy and Hall measurements were used primarily and the relevant analysis was presented in detail. It was found that the low power (60 W) deposition produces more superior optoelectronic properties than the high power (100 W) deposition yielding the resistivity of 1.9 × 10−3 Ω·cm and over 89% average transmittance in the visible spectrum with the considerable improved blue response. The substrate temperature was found to improve optoelectronic properties and over 43% enhancement in the resistivity was achieved at the optimum 150 °C. In both aforesaid cases, improvement in the electrical conductivity was linked to the grain growth and the increase in free carriers. Effect of these two deposition parameters influenced the scale of optoelectronic uniformity, which was analyzed in three spots. Finally, the adverse effect of spatial optoelectronic non-uniformity due to the high power deposition was observed.

ACS Style

Mohammad Tanvirul Ferdaous; Seyed Ahmad Shahahmadi; Megat Mohd Izhar Sapeli; Puvaneswaran Chelvanathan; Akhtaruzzaman; Sieh Kiong Tiong; Nowshad Amin. Interplay between variable direct current sputtering deposition process parameters and properties of ZnO:Ga thin films. Thin Solid Films 2018, 660, 538 -545.

AMA Style

Mohammad Tanvirul Ferdaous, Seyed Ahmad Shahahmadi, Megat Mohd Izhar Sapeli, Puvaneswaran Chelvanathan, Akhtaruzzaman, Sieh Kiong Tiong, Nowshad Amin. Interplay between variable direct current sputtering deposition process parameters and properties of ZnO:Ga thin films. Thin Solid Films. 2018; 660 ():538-545.

Chicago/Turabian Style

Mohammad Tanvirul Ferdaous; Seyed Ahmad Shahahmadi; Megat Mohd Izhar Sapeli; Puvaneswaran Chelvanathan; Akhtaruzzaman; Sieh Kiong Tiong; Nowshad Amin. 2018. "Interplay between variable direct current sputtering deposition process parameters and properties of ZnO:Ga thin films." Thin Solid Films 660, no. : 538-545.

Journal article
Published: 01 June 2018 in Materials Letters
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Cu2ZnSnS4 (CZTS) is highly researched photovoltaic (PV) material in recent years because of resource availability and non-toxicity of its constituents. Radio frequency (RF) magnetron sputtering is one of the potential method of fabricating CZTS thin film due to its suitability to large scale industrial implementation. Of the three methods of depositing CZTS films by RF sputtering, single quaternary target one step sputtering is by far the simplest and straightforward one. However, deposition profile plays a crucial role in maintaining the integrity of pre-defined target composition transferred to deposited samples. In this study, several deposition parameters, such as RF power, working pressure, target to sample distance were varied and their influences on corresponding compositional variation in deposited samples were studied. A quaternary CZTS target of pre-fixed composition of (Cu=22%, Zn=15%, Sn=13%, S=50%) was used to deposit CZTS thin film at various depositing conditions. High RF power was found to be detrimental and was associated with high Cu loss of up to 53% of original atomic composition.

ACS Style

M.T. Ferdaous; P. Chelvanathan; S.A. Shahahmadi; M.M.I. Sapeli; K. Sopian; N. Amin. Compositional disparity in Cu2ZnSnS4 (CZTS) thin film deposited by RF-sputtering from a single quaternary compound target. Materials Letters 2018, 221, 201 -205.

AMA Style

M.T. Ferdaous, P. Chelvanathan, S.A. Shahahmadi, M.M.I. Sapeli, K. Sopian, N. Amin. Compositional disparity in Cu2ZnSnS4 (CZTS) thin film deposited by RF-sputtering from a single quaternary compound target. Materials Letters. 2018; 221 ():201-205.

Chicago/Turabian Style

M.T. Ferdaous; P. Chelvanathan; S.A. Shahahmadi; M.M.I. Sapeli; K. Sopian; N. Amin. 2018. "Compositional disparity in Cu2ZnSnS4 (CZTS) thin film deposited by RF-sputtering from a single quaternary compound target." Materials Letters 221, no. : 201-205.

Journal article
Published: 01 May 2018 in Materials Letters
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In this letter, we report the effects of preferred crystallographic orientation of Mo films on formation of MoS2 layer through elemental sulfurization process. Vacuum thermal annealing of as-sputtered Mo films results in noticeable change in preferred crystallographic orientation from (110) to (211) plane. Correlation between structural and Raman spectroscopy study indicates that, Mo film with predominantly (211) orientation results in pronounced formation of MoS2 compared to film with higher degree of (110) orientation. Planar packing factor which depends on crystallographic orientation is proposed to play a crucial role in determining the degree of MoS2 formation.

ACS Style

P. Chelvanathan; S.A. Shahahmadi; M.T. Ferdaous; M.M.I. Sapeli; K. Sopian; N. Amin. Controllable formation of MoS2 via preferred crystallographic orientation modulation of DC-sputtered Mo thin film. Materials Letters 2018, 219, 174 -177.

AMA Style

P. Chelvanathan, S.A. Shahahmadi, M.T. Ferdaous, M.M.I. Sapeli, K. Sopian, N. Amin. Controllable formation of MoS2 via preferred crystallographic orientation modulation of DC-sputtered Mo thin film. Materials Letters. 2018; 219 ():174-177.

Chicago/Turabian Style

P. Chelvanathan; S.A. Shahahmadi; M.T. Ferdaous; M.M.I. Sapeli; K. Sopian; N. Amin. 2018. "Controllable formation of MoS2 via preferred crystallographic orientation modulation of DC-sputtered Mo thin film." Materials Letters 219, no. : 174-177.

Short communication
Published: 09 March 2018 in Materials Letters
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In this letter, we report the structural and optoelectronic properties of chromium-doped Cu2ZnSnS4 (CZTS:Cr) deposited by co-sputtering technique. Addition of chromium was observed to deteriorate the Cu2ZnSnS4 crystallinity as well as inducing the growth of cubic-ZnCr2S4 secondary phase. Grain size as large as 0.5 µm was observed for the doped sample. Bandgap was found to vary (1.51–1.70 eV), whereas the deep level defect state was calculated to be positioned at 0.20–0.33 eV above the valence band maximum (VBM) depending on the chromium concentration.

ACS Style

M.M.I. Sapeli; M.T. Ferdaous; S.A. Shahahmadi; Kamaruzzaman Sopian; Puvaneswaran Chelvanathan; N. Amin. Effects of Cr doping in the structural and optoelectronic properties of Cu2ZnSnS4 (CZTS) thin film by magnetron co-sputtering. Materials Letters 2018, 221, 22 -25.

AMA Style

M.M.I. Sapeli, M.T. Ferdaous, S.A. Shahahmadi, Kamaruzzaman Sopian, Puvaneswaran Chelvanathan, N. Amin. Effects of Cr doping in the structural and optoelectronic properties of Cu2ZnSnS4 (CZTS) thin film by magnetron co-sputtering. Materials Letters. 2018; 221 ():22-25.

Chicago/Turabian Style

M.M.I. Sapeli; M.T. Ferdaous; S.A. Shahahmadi; Kamaruzzaman Sopian; Puvaneswaran Chelvanathan; N. Amin. 2018. "Effects of Cr doping in the structural and optoelectronic properties of Cu2ZnSnS4 (CZTS) thin film by magnetron co-sputtering." Materials Letters 221, no. : 22-25.

Journal article
Published: 01 January 2018 in Current Applied Physics
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Ejarder Sabbir Hossain; Puvaneswaran Chelvanathan; Seyed Ahmad Shahahmadi; Kamaruzzaman Sopian; Badariah Bais; Nowshad Amin. Performance assessment of Cu2SnS3 (CTS) based thin film solar cells by AMPS-1D. Current Applied Physics 2018, 18, 79 -89.

AMA Style

Ejarder Sabbir Hossain, Puvaneswaran Chelvanathan, Seyed Ahmad Shahahmadi, Kamaruzzaman Sopian, Badariah Bais, Nowshad Amin. Performance assessment of Cu2SnS3 (CTS) based thin film solar cells by AMPS-1D. Current Applied Physics. 2018; 18 (1):79-89.

Chicago/Turabian Style

Ejarder Sabbir Hossain; Puvaneswaran Chelvanathan; Seyed Ahmad Shahahmadi; Kamaruzzaman Sopian; Badariah Bais; Nowshad Amin. 2018. "Performance assessment of Cu2SnS3 (CTS) based thin film solar cells by AMPS-1D." Current Applied Physics 18, no. 1: 79-89.

Journal article
Published: 01 September 2017 in Thin Solid Films
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P. Chelvanathan; S.A. Shahahmadi; F. Arith; K. Sobayel; M. Aktharuzzaman; K. Sopian; F.H. Alharbi; N. Tabet; N. Amin. Effects of RF magnetron sputtering deposition process parameters on the properties of molybdenum thin films. Thin Solid Films 2017, 638, 213 -219.

AMA Style

P. Chelvanathan, S.A. Shahahmadi, F. Arith, K. Sobayel, M. Aktharuzzaman, K. Sopian, F.H. Alharbi, N. Tabet, N. Amin. Effects of RF magnetron sputtering deposition process parameters on the properties of molybdenum thin films. Thin Solid Films. 2017; 638 ():213-219.

Chicago/Turabian Style

P. Chelvanathan; S.A. Shahahmadi; F. Arith; K. Sobayel; M. Aktharuzzaman; K. Sopian; F.H. Alharbi; N. Tabet; N. Amin. 2017. "Effects of RF magnetron sputtering deposition process parameters on the properties of molybdenum thin films." Thin Solid Films 638, no. : 213-219.

Book chapter
Published: 01 January 2017 in Encyclopedia of Sustainable Technologies
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Nowshad Amin; Seyed Ahmad Shahahmadi; Puvaneswaran Chelvanathan; Kazi Sajedur Rahman; Mohammad Istiaque Hossain; M.D. Akhtaruzzaman. Solar Photovoltaic Technologies: From Inception Toward the Most Reliable Energy Resource. Encyclopedia of Sustainable Technologies 2017, 11 -26.

AMA Style

Nowshad Amin, Seyed Ahmad Shahahmadi, Puvaneswaran Chelvanathan, Kazi Sajedur Rahman, Mohammad Istiaque Hossain, M.D. Akhtaruzzaman. Solar Photovoltaic Technologies: From Inception Toward the Most Reliable Energy Resource. Encyclopedia of Sustainable Technologies. 2017; ():11-26.

Chicago/Turabian Style

Nowshad Amin; Seyed Ahmad Shahahmadi; Puvaneswaran Chelvanathan; Kazi Sajedur Rahman; Mohammad Istiaque Hossain; M.D. Akhtaruzzaman. 2017. "Solar Photovoltaic Technologies: From Inception Toward the Most Reliable Energy Resource." Encyclopedia of Sustainable Technologies , no. : 11-26.

Journal article
Published: 01 December 2016 in Materials Science in Semiconductor Processing
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Seyed Ahmad Shahahmadi; A. Aizan Zulkefle; A.K.M. Hasan; S.M. Rana; B. Bais; M. Akhtaruzzaman; A.R.M. Alamoud; Nowshad Amin. Ge-rich SiGe thin film deposition by co-sputtering in in-situ and ex-situ solid phase crystallization for photovoltaic applications. Materials Science in Semiconductor Processing 2016, 56, 160 -165.

AMA Style

Seyed Ahmad Shahahmadi, A. Aizan Zulkefle, A.K.M. Hasan, S.M. Rana, B. Bais, M. Akhtaruzzaman, A.R.M. Alamoud, Nowshad Amin. Ge-rich SiGe thin film deposition by co-sputtering in in-situ and ex-situ solid phase crystallization for photovoltaic applications. Materials Science in Semiconductor Processing. 2016; 56 ():160-165.

Chicago/Turabian Style

Seyed Ahmad Shahahmadi; A. Aizan Zulkefle; A.K.M. Hasan; S.M. Rana; B. Bais; M. Akhtaruzzaman; A.R.M. Alamoud; Nowshad Amin. 2016. "Ge-rich SiGe thin film deposition by co-sputtering in in-situ and ex-situ solid phase crystallization for photovoltaic applications." Materials Science in Semiconductor Processing 56, no. : 160-165.

Journal article
Published: 01 November 2015 in Journal of Nanoscience and Nanotechnology
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Non-hydrogenated amorphous Silicon-Germanium (a-SiGe) thin films were deposited at two different base pressures by RF magnetron co-sputtering. Moreover, an ex-situ thermal annealing was carried out to investigate the material properties to be suitable as the bottom cell of multi-junction solar cells. Compositional study of the films using EDX showed Ge-rich thin films with 75 atomic% of Ge. XRD reflection study implied that all samples were entirely amorphous in nature. However, a significant improvement of morphology possibly due to low base pressure was observed while thermal annealing caused peening and reduction of surface inhomogeneity in both as-sputtered films. UV-VIS-IR analysis confirmed the FESEM results. The highest transmittance was observed in the as-deposited sample grown at 4 x 10(-5) Torr, which however reduced after thermal annealing. Tauc's model was implied for band gap determination and band gap energy as low as 1.07 eV was found in the annealed sample grown at lower base pressure (4 x 10(-6) Torr). Electrical properties of films were investigated by Hall effect measurement system and results found the reduction of resistivity with the same trend of optical band gap energy.

ACS Style

S. A. Shahahmadi; B. Yeganeh; N. Huda; N. Asim; M. Hafidz; M.M. Alam; Z. A. Alothman; K. Sopian; Nowshad Amin. Properties of a-SiGe Thin Films on Glass by Co-Sputtering for Photovoltaic Absorber Application. Journal of Nanoscience and Nanotechnology 2015, 15, 9275 -9280.

AMA Style

S. A. Shahahmadi, B. Yeganeh, N. Huda, N. Asim, M. Hafidz, M.M. Alam, Z. A. Alothman, K. Sopian, Nowshad Amin. Properties of a-SiGe Thin Films on Glass by Co-Sputtering for Photovoltaic Absorber Application. Journal of Nanoscience and Nanotechnology. 2015; 15 (11):9275-9280.

Chicago/Turabian Style

S. A. Shahahmadi; B. Yeganeh; N. Huda; N. Asim; M. Hafidz; M.M. Alam; Z. A. Alothman; K. Sopian; Nowshad Amin. 2015. "Properties of a-SiGe Thin Films on Glass by Co-Sputtering for Photovoltaic Absorber Application." Journal of Nanoscience and Nanotechnology 15, no. 11: 9275-9280.

Journal article
Published: 01 May 2015 in Applied Mechanics and Materials
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This paper presents the performance between silicon germanium (SiGe) and crystalline germanium (Ge) solar cells in terms of their simulated open circuit voltage, short circuit current density, fill factor and efficiency. The PC1D solar cell modeling software has been used to simulate and analyze the performance for both solar cells, and the total thickness is limited to 1μm of both SiGe and Ge solar cells. The Si0.1Ge0.9 thickness is varied from 10nm to 100nm to examine the effect of Si0.1Ge0.9 thickness on SiGe solar cell. The result of simulation exhibits the SiGe solar cell give a better performance compared to Ge solar cell. The efficiency of 9.74% (VOC = 0.48V, JSC = 27.86mA/cm2, FF =0.73) is achieved with Si0.1Ge0.9 layer of 0.1μm in thickness whilst 2.73% (VOC = 0.20V, JSC = 27.31mA/cm2, FF =0.50) efficiency is obtained from Ge solar cell.

ACS Style

Ahmad Aizan Zulkefle; Maslan Zainon; Zaihasraf Zakaria; Mohd Ariff Mat Hanafiah; Nurul Huda Abdul Razak; Seyed Ahmad Shahahmadi; Akhtaruzzaman; Kamaruzzaman Sopian; Nowshad Amin. A Comparative Study between Silicon Germanium and Germanium Solar Cells by Numerical Simulation. Applied Mechanics and Materials 2015, 761, 341 -346.

AMA Style

Ahmad Aizan Zulkefle, Maslan Zainon, Zaihasraf Zakaria, Mohd Ariff Mat Hanafiah, Nurul Huda Abdul Razak, Seyed Ahmad Shahahmadi, Akhtaruzzaman, Kamaruzzaman Sopian, Nowshad Amin. A Comparative Study between Silicon Germanium and Germanium Solar Cells by Numerical Simulation. Applied Mechanics and Materials. 2015; 761 ():341-346.

Chicago/Turabian Style

Ahmad Aizan Zulkefle; Maslan Zainon; Zaihasraf Zakaria; Mohd Ariff Mat Hanafiah; Nurul Huda Abdul Razak; Seyed Ahmad Shahahmadi; Akhtaruzzaman; Kamaruzzaman Sopian; Nowshad Amin. 2015. "A Comparative Study between Silicon Germanium and Germanium Solar Cells by Numerical Simulation." Applied Mechanics and Materials 761, no. : 341-346.