Zinc　sulfide　(ZnS)　buffer　layer　is　one　of　the　most　promising　potential　candidates　for　solar　applications　due　to　its　no　toxicity,　wider　energy　bandgap　compared　with　cadmium　sulfide　(CdS)　buffer　layers.　The　ZnS　thin　films　doped　with　0-4　at%　In　have　been　grown　by　a　Chemical　Bath　Deposition　(CBD)　method.　The　X-ray　diffraction　analysis　indicates　that　all　the　films　show　an　obvious　peak　corresponding　to　(111)　plane　of　cubic　form　ZnS.　All　the　ZnS:　In　films　have　a　high　transmittance　of　about　85%　in　the　visible　region　with　a　high　energy　bandgap　of　about　3.60　eV.　The　electrical　resistivity　of　the　In-doped　samples　is　decreased　from　10(6)　Omega　cm　(undoped　sample)　to　104　Omega.m　after　doping　with　0.5　at%　In.　The　detailed　analysis　about　the　change　of　bandgap,　resistivity　and　other　results　with　the　In　dopant　concentration　would　be　presented　and　discussed.　(C)　2014　The　Electrochemical　Society.　All　rights　reserved.