Seamless monolithic water splitting system using miniaturized crystalline silicon microwire interdigitated back contact photoelectrode

Abstract

We fabricated c-Si based wireless monolithic artificial leaf for an efficient unassisted photoelectrochemical water splitting (PEC). A seamless module was manufactured using a c-Si interdigitated back contact (IBC) structure. Through modularization, a photoelectrode having an overpotential of 1.5 - 2 V or more was realized. So unassisted water splitting was possible. We fabricated a c-Si IBC photoanode that obtained an efficiency of 10.1 % at 0 V (unassisted water splitting). An artificial leaf, an unassisted-wireless water splitting system, was fabricated using the proposed c-Si IBC solar cell and showed about 8.4 % STH, which was the highest performance among the reported silicon-based wireless PEC systems despite no optimization of catalysts. The design suitable for artificial leaf devices and the expectation of improved efficiency through the development of catalysts make the c-Si IBC module artificial leaf system promising for the unassisted photoelectrochemical hydrogen production in practical application.