* Correspondingauthor.Tel.: #372-620-33-62;fax: #372-620-27-98. E-mail address: malle@sta!.ttu.ee(M.Krunks). SolarEnergyMaterials&SolarCells69(2001)93}98 SprayedCuInS  thin "lmsforsolarcells: Thee!ectofsolutioncompositionand post-depositiontreatments M.Krunks*,O.Bijakina,V.Mikli,H.Rebane, T.Varema,M.Altosaar,E.Mellikov Institute of Materials Technology, Tallinn Technical University, Ehitajate 5, 19086 Tallinn, Estonia Centre for Materials Research, Tallinn Technical University, Ehitajate 5, 19086 Tallinn, Estonia Received16August2000 Abstract CuInS  thin "lmswerepreparedbyspraypyrolysisfromsolutionswithdi!erentcomposi- tions.EtchinginKCNsolutionandthermaltreatmentsinvacuumandhydrogenwereapplied to as-deposited "lms. KCN etching removes conductive copper sul"de from the surface of Cu-rich "lms but has no e!ect on matrix composition. Vacuum annealing at 5003C and hydrogen treatment at 400}5003C puri"es the "lms, prepared from the solutions with the Cu/In"1,fromsecondaryphases,reduceschlorinecontentandimprovescrystallinity.Vac- uum annealing results in n-type "lms due to the formation of In  O  phase. Treatment in hydrogenreducesoxygen-containingresiduesandresultsinp-typeCuInS  "lmswithresistivity closeto10  cm.  2001ElsevierScienceB.V.Allrightsreserved. Keywords: Copperindiumdisul"de;Thin "lms;Spraypyrolysis;Hydrogentreatment;Vacuumannealing 1. Introduction Thehighproductioncostoftheconventionalsolarcellsrequiresasearchinorder tolookforcheapermethodsandmaterialsforsolarenergyconversion.Thesimple and cheap spray pyrolysis method is a widely used process to produce large-area 0927-0248/01/$-seefrontmatter  2001ElsevierScienceB.V.Allrightsreserved. PII:S0927-0248(00)00381-0