This paper reports on reduced graphene oxide (rGO), tin oxide (SnO₂) and polyvinylidene fluoride (PVDF) tertiary nanocomposite thick film based flexible gas sensor. The nanocomposite of 0.90(PVDF) − 0.10[x(SnO₂) − (1 − x)rGO] with different weight percentages (x = 0, 0.15, 0.30, 0.45, 0.6, 0.75, 0.90 and 1) have been prepared by the hot press method. Chromium (Cr) has been deposited on the surface by using E-beam evaporation system, which is used as electrode of the device. Crystal structure, morphology, and electrical characteristics of the device have been explored for the technological application. A correlation between crystallinity, morphology, and electrical properties with these thick films has also been established. The device has been tested at different hydrogen (H₂) gas concentration as well as at different response times. A superior response of 0.90(PVDF) − 0.10[0.75(SnO₂) − 0.25 rGO] nanocomposite thick film has been observed. Hence, this composition is considered as optimized tertiary nanocomposite for the hydrogen gas sensor application. The sensor response of 49.2 and 71.4% with response time 34 sec and 52 sec for 100 PPM and 1000 PPM H₂ gas concentration respectively have been obtained. First time a new kind of low cost and flexible polymer based nanocomposite thick film gas sensor has been explored.

This study conducted a simulative analysis of different hybrid perovskite solar cells with various hybrid electron transport layers (ETL) and hole transport layers (HTL). The electron transport layer boosts durability, lowers production costs, increases stability, improves light absorption, and increases efficiency. Hybrid ETLs are taken into consideration to improve the device's performance. The selected hybrid ETLs (PCBM–SnS₂, TiO₂–SnO₂, and PCBM–PCPB) were modeled with four hybrid perovskite absorbers (CsPbI₃, FAPbI₃, MAPbI_3, and FAMAPbI₃) and five HTLs (PEDOT: PSS, CuI, Spiro-OMeTAD, CBTS, and NiO). Three sets of solar cells are found to be the most effective configurations after investigating over sixty different combinations of perovskite solar cell architectures. The structures show CBTS as the efficient HTL for FAMAPbI₃ with all three hybrid ETLs. Besides, a holistic analysis of the effect of several factors such as the defect density and thickness of the absorber layer, temperature, parasitic resistances, capacitance, Mott–Schottky, impedance, conduction band offset, and current density–voltage and quantum efficiency characteristics is performed. The results show a maximum power conversion efficiency of 25.57%, 26.35%, and 23.36% with PCBM–SnS₂, TiO₂–SnO₂, and PCBM–PCPB respectively. Among the studied hybrid ETLs, perovskite solar cell associated with TiO₂–SnO₂ has depicted a superior performance (Voc = 1.12 V, Jsc = 26.88 mA/cm², FF = 87.27%). The efficiency of the perovskite solar cell using this study has been drastically enhanced compared to the previous experimental report. The proposed strategy provides a new avenue for attaining clean energy and allows researchers to pave the way for further design optimization to obtain high-performance solar cell devices.

An ultrasensitive ammonia gas sensor based on hydrothermally synthesized rGO/WO3 nanocomposite with interdigitated chromium electrode has been fabricated. Device properties such as structural, morphological, optical, and electrical were analyzed and reported. A correlation between stability and performance of the device with electrical properties has been established. Sensor shows excellent selectivity and sensitivity towards ammonia detection, even at lower gas concentration and low operating temperature. At room temperature, the sensor depicts the sensing response 4.35 with 13/20 sec response/recovery time for 10 PPM NH3 gas concentration. Although the best sensing performance has been obtained for 150 °C operating temperature. For 10 PPM and 100 PPM NH3 gas concentration, we found sensor response 10.89 and 27.7 with 11/17 and 7/19 sec response/recovery time. The sensor has been tested for different period/interval of time and found that the proposed nanocomposite has excellent stability and reproducibility thus can be utilized for various gas sensing applications.

This paper reports a comparative study of electron-beam evaporated ZnO, MgZnO, and CdZnO thin film based-gas sensor. At room temperature (RT), these semi-conductive thin films were deposited on Si/SiO2 substrate and an interdigitated pattern of chromium electrode deposited on these films. Device properties, such as structural, optical, and electrical, have been reported and analyzed. The sensors have been tested at different operating temperatures. At 250 °C, the sensor shows the best response for CdZnO thin films. We have obtained sensor response 4.86 with response time 15 sec for 100-PPM carbon mono oxide (CO) gas concentration for CdZnO thin film. Based on experimental results, Cd-doped ZnO has been found most suitable among these semiconducting metal oxides, when used as a CO gas sensor. A correlation between structural, optical, and electrical properties with these thin films has also been established.