Investigation On New Aspects of CZTS Multi Layer Solar Cell For Photovoltaic Application

Abstract

Form the past few decades, the earth has been looking for safer and more newlineappropriate replacement to traditional energy sources such as wind, solar, newlinehydrothermal, ocean, etc., Among these, solar photovoltaic (PV) is most efficient, as newlinesolar energy is abundant and safe from contamination. Till now amorphous Silicon (a- newlineSi), Copper Indium Gallium Selenide (CIGS) and Cadmium Telluride (CdTe) were newlinecurrently available on the market for thin film technologies. CIGS and CdTe has newlinelargest share in the market of thin film technologies. Usage of scares and costly newlineelement like indium and tellurium are drawback to CIGS and CdTe technologies. newlineIt is indeed evident that there will be problems of long-term viability in terms of newlineprice and sustainability of the elements, mostly in case of the CdTe and CIGS newlinetechnologies. In this context research is started in search of alternative non-toxic newlineabsorber material. Cu2ZnSnSe4 (CZTSe) and Cu2ZnSnS4 (CZTS) are advantageous newlinesubstitute absorber materials in thin-film photovoltaic cells for its p-type nature, high newlineabsorption coefficient (gt 104 cm-1) and optimum direct band gap (~1.5eV). Copper newlineZinc Tin Sulphide comprises of earth abundant, environmentally safe and affordable newlinematerials. Fabricating quaternary material with phase pure form of CZTS is a newlinechallenge. There is a small formulation area for Cu2ZnSnS4 at 670 K, Cu/(Zn+Sn) newlineand Zn/Sn ratios may differ between 0.94 and 1.07. Cu2ZnSnS4 coexists with different newlinephases, like Cu2ZnSn3S8, ZnS, Cu2S, Cu4SnS4 and Cu2SnS3, etc. This demonstrates the newlineimportance of conducting research into the development aspects of this material. This newlinewould eventually lead to phase-pure CZTS with optimized photovoltaic newlinecharacteristics. newlineThe conductivity of the CZTS absorber is p-type due to its intrinsic point newlinedefects. CZTS formation is a very small window, it is quite crucial to observe the newlineconditions of deposition. The films must be fabricated under z-rich and cu-poor newlineconditions, that will create the appropriate device defects. This helps in the prevention newlinein develo