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

Highlights: • High quality thin films of MoS₂ and WS₂ were grown on p-Si using one-step thermal chemical vapor deposition. • MoS₂/WS₂ and WS₂/MoS₂ heterostructures were created by thermal chemical vapor deposition. • MoS₂/p-Si as single junction showed J_sc values of 0.31 µA/cm². • MoS₂/p-Si showed low series resistance than that of pristine WS₂ and heterostructures MoS₂ and WS₂. • Role of layer arrangement in power conversion efficiency of heterostructures is investigated. 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.