Optimization of the Shell Thickness of the ZnO/CdS Core-Shell Nanowire Arrays in a CZTS Absorber

Abstract

Copper-zinc-tin-sulfide (CZTS) solar cells have now become a topic of interest in the solar power generation industry. These are used as an absorber in the zinc oxide (ZnO)/cadmium sulfide (CdS) core-shell nanowire arrays, in order to improve the performance of solar cells. The relationship between the average increase in absorption rates and CdS shell thickness (compared to the thin film) reveals that the optimum thickness with the maximum average absorption rate (39.95%) compared to thin film is 30 nm. The cells’ electrical and optical performance was significantly improved with the introduction of graphene between the ZnO and CdS layers. The shell thicknesses for a better performance of these nanowire solar cells were 30 and 40 nm, with almost the same open-circuit voltage, the similar short-circuit current density, and efficiency, which were 630 mV, 6.39 mA/cm2, and 16.8%, respectively. Furthermore, a minimum reflection of 40% was obtained with these same shell thicknesses.

Recent progress in solar cells based on one dimensional ZnO nanostructures

“…Among them, the ZnO NWs are of particular interest in solar cell applications and have been widely researched in the literature. Wang et al reported a simulation study involving the optimization of the shell thickness of CdS decorated ZnO NW arrays in a CZTS absorber layer as an attempt to enhance the optical and electrical performance of ZnO-NWs/CdS/CZTS structured solar cell [86]. The COMSOL Multiphysics program was preferred to reveal the optical performance of the device structures built with various CdS shell thicknesses.…”

Simulation of a New CZTS Solar Cell Model with ZnO/CdS Core-Shell Nanowires for High Efficiency

“…It has also been shown that under certain conditions, the contact of graphene with the single layer of MoS 2 effectively improves photon absorption and photocatalytic efficiency [34][35][36][37]. Chonge Wang et al showed by simulation that the introduction of a graphene nanolayer between the ZnO core and the CdS shell could lead to an improvement in the optical absorption of the cell [38]. This shows that it is interesting to study the optical and electrical performance of the model in which graphene is sandwiched between the core and the shell and also deposited on the MoS 2 layer.…”

“…Other studies also performed on the solar cell model based on ZnO/CdS core-shell nanowire arrays resulted in a maximum absorption of 92% at a wavelength of 500 nm [58]. Chonge Wang et al, by simulation on ZnO/CdS core-shell nanowire arrays, by including graphene in the CZTS-based solar cell structure, obtained Jsc = 6.39 mA/cm 2 , Voc = 0.63 V, EFF = 16.8%, and a maximum absorption and reflection of 97% and 40%, respectively [38].…”