Quasi-Heteroface Perovskite Solar Cells
【摘要】：In order to further improve the PCE of Perovskite solar cells(PSCs), new possible optimization path needs to be found. Here, quasi-heteroface PSCs(QHF-PSCs) is designed by a doublelayer perovskite film. Such brand new PSCs have good carrier separation capabilities, effectively suppress the nonradiative recombination of the PSCs, and thus greatly improve the open-circuit voltage and PCE. The root cause of the performance improvement is the benefit from the additional built-in electric field, which is confirmed by measuring the external quantum efficiency under applied electric field and Kelvin probe force microscope. Meanwhile, an intermediate band gap perovskite layer can be obtained simply by combining a wide band gap perovskite layer with a narrow band gap perovskite layer. Tunability of the band gap is obtained by varying the film thicknesses of the narrow and wide band gap layers.