P-type doping in internally photoemitted hot carrier solar cells

Hot carriers in hybrid perovskite have been proven to have eminent properties with long carrier cooling time and long carrier migration distance. The invention of the internally photoemitted hot carrier (IPHC) solar cell recently makes it possible to utilize the hot electrons in CH3NH3PbI3 perovskite and capture their excess energies under steady state illumination. How to further improve the efficiency of IPHC cells is challenging and crucial to demonstrate their effectiveness. In this work, sodium iodide (NaI) is added into the CH3NH3PbI3 precursor solution for inducing a P-type doping and downshifting its Fermi level. The lowered energy barrier at the interface of Au/doped CH3NH3PbI3 promotes the hot electron extraction, thereby enhancing the power conversion efficiency of IPHC devices. The FTO/TiO2/Au/Na+-doped MAPbI3 construction with considerable photocurrent would be an alternative approach for light-to-electricity conversion.