Numerical simulation of solar cells besed CZTS buffer layer (ZnO1-XSX) using SCAPS-1D software

Cds buffer layer has many advantages such as large bandgap, and the carrier density. Otherwise, the presence of cadmium is an inconvenient. Research work, are shifted on the possibility of replacing CdS by a buffer layer devoid of cadmium. This manuscript presents the numerical study, using SCAPS-1D program, the effects of sulfur content in the buffer layer Zn (O,S) on the electrical parameters of the solar cell ZnO: Al / i-ZnO / Zn (O, S) / CZTS /. Changes in the band gap and electron affinity of Zn (O, S) were calculated from the law of Vegard. The numerical results of the thickness of the absorbent layer CZTS equal to 2.5μm, show that from the sulfur content equals to 45% we can find the same results with CdS, an efficiency varies slightly, about 19%.Keywords: CZTS; ZnO1-xSx; CdS; SCAPS; Solar cell

Acetone sensor based on Ni doped ZnO nanostructues: growth and sensing capability

This work presents the preparation of nanostructured zinc oxide (ZnO) thin films doped nickel (Ni) with the molar ratios [Ni]/[Zn]=0.5; 1; 1.5; 2% M, using low cost spray pyrolysis method. Different characterization techniques were established, such as: X-ray diffraction that showed the hexagonal structure of the films confirmed by Raman spectroscopy. The grain size variations and the morphology according to doping levels were analyzed by scanning electron microscopy. Optical analysis was carried out, the films are transparent and the band gap energy varies opposing to Urbach energy. From experimental data, we observed that 2% Ni doped ZnO exhibited good characteristics and properties compared to pure ZnO and followed by the other samples. The gas testing confirmed the previous concepts, proving that 2% of nickel added to the basic solution enhanced; response/recovery time, response of the sensor and optimal working temperature. This sample demonstrated better selectivity to acetone detection with high response reaching 90, at 450 degrees C under 100ppm

Impact of Sn doping on the hydrogen detection characteristics of ZnO thin films: Insights from experimental and DFT combination

The development of efficient chemical sensors based on semiconductor oxides is a major challenge. Low-cost equipment fabrication with a high sensor response towards H2 was the aim of our work. Chemical sensors were elaborated using zinc oxide, aluminum- and tin-doped zinc oxide. The samples were synthesized with a cost-effective chemical spray pyrolysis technique. Sn-doped ZnO response to hydrogen gas is the highest followed by ZnO and Al-doped ZnO, with a high sensitivity reaching 200 at 500 ppm, for 400 °C. DFT calculations revealed that O2 is strongly adsorbed on the ZnO-Al surface, resulting in the cancellation of the electrical conductance. Consequently, the approaching H2 gas will not possess sufficient energy to extract the strongly adsorbed oxygen from the surface, and no trapped electrons can be released back to the surface. In contrast, DFT calculations highlighted the potential of ZnO and Sn-doped ZnO to be used as hydrogen gas sensors. Charge transfer analysis revealed that only a small release of the trapped electrons occurs on the pure ZnO surface (0.14|e|), compared to Sn doped ZnO, in which a full release of free electrons was observed, resulting in a more favorable response to H2 and confirming the experimental results