Promise of commercialization: Carbon materials for low-cost perovskite solar cells

Cai Yu^{1, 2}, Liang Lusheng², Gao Peng^{2, †}

(color online) Device structure and energy-level diagram: (a) schematics of the whole device: FTO glass/compact TiO₂ layer/mesoporous TiO₂/CH₃NH₃PbI₃ capping layer/CuPc/carbon and (b) the corresponding energy level diagram. Fabrication process flow for the instant inkjet printing of the C/CH₃NH₃PbI₃ planar perovskite solar cells. For comparison, a different strategy was used to convert PbI₂ into CH₃NH₃PbI₃ using separate step 3 and step 4. Reprinted from Ref. [50].