TiO2 composite electron transport layers for planar perovskite solar cells by mixed spray pyrolysis with precursor solution incorporating TiO2 nanoparticles
Tian Jiaqi, Li Hongcui, Wang Haiyue, Zheng Bo, Xue Yebin, Liu Xizhe
       

Surface morphology of TiO2 layers without (a) and with incorporation of 25 nm (b), 60 nm (c), and 100 nm (d) TiO2 nanoparticles. The scale bar is 200 nm.