Abstract

• To improve the performance of the perovskite solar cells (PSCs), the bottom Electron Transport Layer (ETL) is plays a critical role in extracting and transporting the photo-generated electrons as well as blocking holes to reduce charge recombination. In the present work, SnO2 thin films were prepared by chemical bath deposition method. The optical properties and surface properties of resulted films were characterized by using UV-vis spectrophotometry and water contact angle measurements. The optical band gap of SnO2-CBD (180℃) and SnO2-CBD (500 ℃) are found to be 3.42 eV and 3.88 eV respectively. Excellent transmittance of SnO2-CBD (180 ℃) film showed over 90 % than that of SnO2CBD annealed at 500 ℃. Hydrophobic properties of the surface are closely related to the crystalline behavior of the SnO2 films at 180 ℃ confirmed by Water Contact Angle measurement.