Nanocrystalline diamond on Si solar cells for direct photoelectrochemical water splitting

Abstract

This article presents a study of a boron‐doped nanocrystalline diamond (B‐NCD) and crystalline silicon solar cell (c‐Si SC) heterostructure designed for direct photoelectrochemical water splitting application. A system is proposed which generates voltages sufficient for water‐splitting via light absorption by solar cells. The rear side (photo‐anode) of the c‐Si solar cell was shielded with the B‐NCD layer intended to serve as a protective coating to eliminate corrosion of the Si and operate as a p‐type conductive electrode suited for water decomposition. Information on the efficiency of the c‐Si/B‐NCD heterostructure and the distribution of the electric potential has been gained through investigation of minority carrier recombination mapping. The results of the B‐NCD layer characterization by Raman spectroscopy, AFM, SEM and optical reflection measurements are presented. It is demonstrated that inclusion of a boron (p+) diffusion layer into a c‐Si solar cell structure prevents lifetime (LT) degradation caused by the B‐NCD deposition process. In addition it is shown that the B‐NCD deposition temperature has a substantial effect on the properties of c‐Si solar cell.