Optoelectronic studies of Copper sulfide selenide (CuSSe) nanorods for its application as a potential absorber layer in photovoltaics

Abstract

CuSSe nanorods using Polyvinylpyrrolidone (PVP) as a capping agent are synthesized through chemical bath deposition for its fruitful application in photovoltaic devices. A design and simulation of photovoltaic characteristics using CuSSe as a potential absorber layer have been done employing SCAPS-1D. Material properties of CuSSe are optimized prior to simulation. XRD results confirm mixed hexagonal phases of CuSe and CuS in CuSSe nanorods. HRTEM as well as FESEM images clearly exhibit the rod-shaped morphology for CuSSe. The absorption edge is continuously shifted from 476 nm for the Cu50S10Se40 to 826 nm for Cu50S40Se10 and the optical band gap changes up to 1.5eV which is the optimum value for a light absorber layer. The change in absorption edge in CuSSe alloy is attributed to the phase transition of cubic CuSe to hexagonal CuSSe structure. Photoluminescence also shows a sharp reduction of intensity as we decrease the Se/S ratio for the CuSSe nanorods which makes it a suitable active material for the photovoltaic device. The conductivity noticeably enhanced for CuSSe rods over that of CuSe and CuS. Thus for a theoretical approach, a solar cell design Al/MgF2/ZnO: B/i-ZnO/CdS/Cu-S-Se/Mo/Substrate have been made for simulation studies. The J-Vcharacteristics of the simulation show efficiency of 16.58% and 13.49% for the ternary chalcogen of band gap 1.5eV–1.7eV at absorber thickness of 2000 nm. This study thus implies that chemically synthesized CuSSe nanorods may be used as a potential absorber layer for photovoltaic applications.