Copper　indium　sulfide　(CuInS2,　CIS)　photo-absorber　layer　fabricated　by　solution-processed　strategies　have　received　significant　attention　in　development　of　thin-film　solar　cell.　The　superstrate　Au/CIS/CdS/TiO2　thin-film　solar　cell　was　constructed　on　a　single　FTO　substrate.　The　CdS　deposited　TiO2　nanostructures　were　prepared　by　chemical　bath　deposition　to　form　a　uniform　CdS　buffer　layer.　Furthermore,　CIS　solutions　containing　copper,　indium　and　sulfur　precursors　were　spin-coated　to　yield　p–n　junctions　between　CIS　and　CdS.　The　CIS　based　solar　cell　performance　was　investigated　by　optimizing　devices　to　achieve　an　efficient　light　harvesting　and　transport　of　photo-generated　charge　carriers.　The　performances　of　solar　cells　were　optimized　to　be　1.2%　of　PCE.　It　is　considered　that　the　presence　of　both　dense-TiO2　layer　which　acts　as　a　blocking　layer　and　porous　TiO2　which　tightly　holds　CdS　and　CIS,　improve　the　solar　cell　performance　due　to　a　highly　efficient　charge　separation.　These　present　results　suggest　that　CIS　superstrate　solar　cells　prepared　by　facile　nano-structuring　approaches　provide　stable　and　efficient　low-cost　photovoltaic　devices.　©　2021,　Springer　Nature　B.V.