title: Deposition of ultra thin CuInS₂ absorber layers by ALD for thin film solar cells at low temperature (down to 150 °C).
abstract: Two new processes for the atomic layer deposition of copper indium sulfide (CuInS₂) based on the use of two different sets of precursors are reported. Metal chloride precursors (CuCl, InCl₃) in combination with H2S imply relatively high deposition temperature (Tdep = 380 °C), and due to exchange reactions, CuInS₂ stoechiometry was only achieved by depositing In₂S3 layers on a CuxS film. However, the use of acac- metal precursors (Cu(acac)₂, In(acac)₃) allows the direct deposition of CuInS₂ at temperature as low as 150 °C, involving in situ copper-reduction, exchange reaction and diffusion processes. The morphology, crystallographic structure, chemical composition and optical band gap of thin films were investigated using scanning electronic microscope, x-ray diffraction under grazing incidence conditions, x-ray fluorescence, energy dispersive spectrometry, secondary ion mass spectrometry, x-ray photoelectron spectroscopy and UV-vis spectroscopy. Films were implemented as ultra-thin absorbers in a typical CIS-solar cell architecture and allowed conversion efficiencies up to 2.8%.
authors.affiliation: Institut de Recherche et Développement sur l'Energie Photovoltaïque (IRDEP), UMR 7174 EDF-CNRS-Chimie ParisTech, 6 quai Watier, F-78401, Chatou, France.
authors.forename: Nathanaelle
authors.initials: N
authors.lastname: Schneider
authors.forename: Muriel
authors.initials: M
authors.lastname: Bouttemy
authors.forename: Pascal
authors.initials: P
authors.lastname: Genevée
authors.forename: Daniel
authors.initials: D
authors.lastname: Lincot
authors.forename: Frédérique
authors.initials: F
authors.lastname: Donsanti