Deposition of CuInS₂ Thin Films Using Copper- and Indium/Sulfide-Containing Precursors through a Two-Stage MOCVD Method

Abstract

Copper indium disulfide (CuInS2; CIS) films were deposited on various substrates by two-stage metal-organic chemical vapor deposition (MOCVD) at relatively mild conditions, using Cu- and In/S-containing precursors without toxic H2S gas: first, a pure Cu thin film was prepared on glass or indium/tin oxide glass substrates by using a single-source precursor, bis(ethylbutyrylacetato)copper(II) or bis(ethylisobutyrylacetato)copper(II); second, on the resulting Cu film, tris(N,N-ethylbutyldithiocarbamato)indium(III) was treated to produce CIS films by a MOCVD method at 430 degrees C. In this process, their thicknesses and stoichiometries were found to be elaborately controlled on demand by adjusting the process conditions. The optical band gap of the stoichiometric CIS film was about 1.41 eV, which is in the near-optimal range for harvesting solar radiation energy.

MOCVD of thin film photovoltaic solar cells—Next-generation production technology?

“…Various MOCVD processes have been used to synthesis the absorber layer and some have followed the multi-step approach. Lee et al [13] deposited CIS films using a two-step MOCVD process, where a Cu film was deposited in the first step followed by a combined InSe precursor for the second step. A challenge for MOCVD deposition is the low volatility of Cu precursors, which normally requires working at source temperatures above 80 1C.…”

Control of III/VI Ratios in the Preparation of ln2Se3 thin Films

“…Different band-gap energy in CIS thin films has been reported by other groups. 6,8,10,11 Various band gaps of thin films are due to the effects of grain size and thickness of thin films. 11 We demonstrate that an energy band gap of CIS thin films lower than 0.9 eV can be obtained.…”

“…Methods reported for growing CIS thin films include: molecular beam epitaxy (MBE), 3 electrochemical synthesis, 4 evaporation, 5 selenisation 6 and metal organic chemical vapour deposition (MOCVD). 7,8 MOCVD is a well-known technique, that can control the structure of deposited films and grow highquality thin films by using proper precursors. Single-source precursors have been used for deposition of CIS thin films by MOCVD.…”

“…Single-source precursors have been used for deposition of CIS thin films by MOCVD. 7,8 Lee et al 7 used the single-source precursor, bis(ethylbutyrylacetato)copper(II), on glass substrates, and treated it with tris(N,N-ethylbutyldithiocarbamato)indium (III) to produce CIS films by MOCVD. This technique can successfully grow CIS thin films on various substrates such as glass and ITO glass.…”

Synthesis and Characterization of HgII/Se/CuI Multinuclear Compounds from Mercury(II) Bis(p‐aminobenzeneselenolate) – Hg(SeC6H4NH2‐p)2

“…The study of metal chalcogenide (ME) and metal chalcogenolate (MER) compounds has been actively investigated in the last two decades, due to their application in several fields of study, such as nanomaterials, opto‐electronics,, photovoltaics, and biochemistry , . The synthesis of metal chalcogenolates with well‐defined, atomic‐precise structures are of particular interest because of their use as single‐source precursors to nanocrystalline semiconductors …”