Prospect of single and coupled heterojunction solar cells based on n-MoS2 and n-WS2

Abstract A novel structure is proposed for single heterojunction solar cells based on n-type molybdenum disulfide (MoS2) and tungsten disulfide (WS2) deposited on p-type silicon substrate using thermal chemical vapor deposition. Moreover, the coupled heterostructures namely MoS2/WS2 and WS2/MoS2 are prepared by the same method. The main aim of this study is to evaluate the photovoltaic characteristics of the proposed heterojunction solar cells. For this purpose, various characterization techniques namely X-ray diffraction, field emission scanning electron microscopy, diffuse reflectance and Raman spectroscopies are employed. XRD patterns confirm MoS2 and WS2 layers form in hexagonal structures. Furthermore, DRS and Raman spectroscopy confirm the formation of few layers of MoS2, WS2, MoS2/WS2 and WS2/MoS2 heterostructures. The greatest power conversion efficiency (PCE) is obtained for the proposed solar cell fabricated based on MoS2 on p-type Si as single junction. This approach has suitable scientific input for application in photovoltaic cells and optoelectronic devices.