Promise of commercialization: Carbon materials for low-cost perovskite solar cells
Cai Yu1, 2, Liang Lusheng2, Gao Peng2, †
       

(color online) (a) The crystal structure of CH3NH3PbI3 perovskite and the corresponding energy levels of TiO2, CH3NH3PbI3, and carbon. (b) A schematic structure of the carbon-based monolithic device. Reprinted from Ref. [18].