Cesium-doped methylammonium lead iodide perovskite light absorber for hybrid solar cells

Cesium-doped methylammonium lead iodide perovskites are developed as light absorbers for inverted-type perovskite/fullerene planar heterojunction hybrid solar cells. Cesium doping remarkably improves device efficiency from 5.51% to 7.68% due to increases in JSC and VOC via improved light absorption, film morphology and a widening of the energy difference between the valence band of the perovskite and LUMO level of PCBM.