Characterization of CuInS ₂ Thin Films Grown by Close-spaced Vapor Sulfurization of Co-sputtered Cu–In Alloy Precursors

Abstract

Cu–In alloy films were prepared on bare or Mo-coated glass by co-sputtering from Cu and In targets at ambient temperature. The formation of CuInS2 films was accomplished by sulfurization within a graphite container under high S vapor pressure. X-ray diffraction (XRD) analysis of the alloy films showed predominant variation of the phases from In→CuIn2→Cu11In9 as the Cu content in the films increased. The sulfurized In-rich films formed the CuIn5S8 phase that steadily transformed into CuInS2 as film composition changed toward the Cu-rich region. SEM analysis showed different morphologies for the CuIn5S8 and CuInS2 films. Cu-rich films exhibited very dense crystal structures. EDX composition measurements on the films showed Cu/(Cu+In) varying from 0.21 to 0.64 and S/(Cu+In) from 0.80 to 1.36. Resistivities in the range of 2.36 to 1.7×108 Ω·cm were obtained. Studies of the growth mechanism indicated formation of CuIn5S8 as the main secondary phase in both Cu-rich and In-rich films at low temperatures before conversion into CuInS2 at temperatures >400°C.

Pressure-dependent real-time investigations on the rapid thermal sulfurization of Cu–In thin films

“…A parallel reaction path through binary sulfides (InS, and CuS and Cu 2Àx S) and passing through an In-richer cubic CuIn 5 S 8 spinel phase also exists. This path had already been reported in other experiments [22,30] and is supposed to exist because of the evolving and much higher sulfur pressure (from 1 Â10 À4 to 1 mbar) in the reaction chamber. The formation of the binary sulfides is favoured at higher pressures as soon as liquid In is available.…”

Photoelectrochemical performances of AgInS2 film electrodes fabricated using the sulfurization of Ag–In metal precursors

“…The structure of the container was similar to that used for the sulfurization of CuInS 2 [28]. The Ag-In metal precursors and sufficient elemental sulfur were placed in the container and loaded into an evacuated quartz tube with a vacuum of around 10 À 3 Torr.…”

Alternative deposition methods of copper and silver indium ternary sulphides with spinel structure

“…Only few attempts to produce CuIn 5 S 8 and AgIn 5 S 8 thin films are known in the literature [6,7]. In another paper [8], the spinel phase (CuIn 5 S 8 ) was observed as a transfer phase during an In-rich preparation of CuInS 2 films, but the properties of the pure spinel film were not studied. In a previous paper [9] we reported about the preparation of the spinel thin films by conventional sulphurisation of a metallic precursor.…”