Abstract
The majority of high-performance perovskite and polymer solar cells consist of a TiO2 electron transport layer (ETL) processed at a high temperature (>450 degrees C). Here, we demonstrate that low-temperature (80 degrees C) ETL thin film of TiOx:Zn1-xCdxS can be used as an effective ETL and its band energy can be tuned by varying the TiOx:Zn1-xCdxS ratio. At the optimal ratio of 50:50 (vol%), the MAPbI(x)Cl(1-x) perovskite and PCBTBT:PC70BM polymer solar cells achieved 9.79% and 4.95%, respectively. Morphological and optoelectronic analyses showed that tailoring band edges and homogeneous distribution of the local surface charges could improve the solar cells efficiency by more than 2%. We proposed a plausible mechanism to rationalize the variation in morphology and band energy of the ETL.