Different depositing amount of CuInS2 on TiO2 nanoarrays for polymer/CuInS2-TiO2 solar cells

This paper reports the deposition of CuInS2 on TiO2 nanoarrays, with different depositing amounts and demonstrates the application of TiO2-CuInS2 composites in polymer-based solar cells. The composites of TiO2-CIS1 and TiO2-CIS2 were prepared by the deposition of CuInS2 on TiO2 with one-step or two-step solvethermal reactions, respectively, and characterized by XRD, SEM, TEM, absorption spectrum and PL spectrum. Results showed that TiO2-CIS1 displayed the higher light-harvesting ability and PL quenching efficiency compared to TiO2-CIS2, although less CuInS2 was deposited on TiO2 surface. As a result, polymer/TiO2-CIS1 solar cells displayed much higher Jsc correlated with the increased absorptivity and charge separation efficiency, and the higher Voc was originated from the presence of strong interaction between TiO2 and CuInS2 in TiO2-CIS1 resulting in the effective modification of TiO2 surface by CuInS2.