Formation of p-type CuInS₂ absorber layers via sulfurization of co-electrodeposited Cu–In precursors

Abstract

The electrodeposition of Cu-In alloy precursors with suitable stoichiometry and consisting mainly of intermetallic compounds, followed by sulfurization, is a promising method to form good quality CuInS 2 thin films. In this work, Cu-In precursors forming intermetallic compounds were electrodeposited from an acidic solution on Mo substrates at 50 C and sulfurized to form p-type CuInS 2 absorber layers. We studied the crystal structure and compositional characteristics of films before and after sulfurization.Intermetallic compounds, namely Cu 11 In 9 and Cu 9 In 4 , have been observed for precursor films suitable to form CuInS 2 , and p-type CuInS 2 phase with small amounts of CuS was formed, showing the chalcopyrite and CuAu-type ordered phases for Cu/In ratios between 1.09-1.34. The carrier density was increased with increasing Cu/In ratio, but the photoelectrochemical response of the films was not directly related to this ratio. Film morphology has a critical influence on the photocurrent response. The highest photoelectrochemical current was achieved from compact and smooth precursors that were electrodeposited at À1.3 V while the lowest value was obtained with a rough dendritic precursor that was electrodeposited at À1.6 V.

Recent Advances in CuInS2-Based Photocathodes for Photoelectrochemical H2 Evolution

“…Here, Cu and In are electrochemically deposited on conductive substrates in an electrolytic solution [42]. Co-deposition has also been performed to fabricate Cu-In alloy films [21]. Simultaneous electrodeposition of three elements can be performed in a Cu-In-S ternary electrolytic bath.…”