In-Search of Efficient Anti-Reflection Coating Layer for Crystalline Silicon Solar Cells: Optimization of the Thickness of Niobium Pentoxide Thin Layer

The purpose of providing an anti-reflection coating (ARC) layer on the surface of crystalline silicon (c-Si) solar cells is to stipulate a unique dielectric material medium that causes destructive interference of the reflected light from device surfaces and minimize the reflection of light. In this work, the thickness optimization of niobium pentoxide (Nb2O5) as an ARC layer for the high photovoltaic performance of c-Si solar cell was carried out by a low-cost, sol-gel spin coating deposition process and further experimental results were validated by a personal computer one dimensional (PC1D) simulation study. The lowest average reflectance of ~7.21% was achieved at 75 nm thickness of ARC layer as compared to other samples. For simulation study, the different thicknesses of ARC layers were selected as input parameters to explore the photovoltaic characteristics of c-Si solar cells. The simulated results showed that the highest power conversion efficiency (PCE) of 17.92% and over 95% external quantum efficiency (EQE) were achieved with 75 nm thickness of ARC layer based c-Si solar cell. This work on the thickness optimization of the ARC layer would provide the useful information to develop the low-cost high-performance c-Si solar cells.