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 CH 3 NH 3 PbI 3 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 CH 3 NH 3 PbI 3 precursor solution for inducing a P-type doping and downshifting its Fermi level. The lowered energy barrier at the interface of Au/doped CH 3 NH 3 PbI 3 promotes the hot electron extraction, thereby enhancing the power conversion efficiency of IPHC devices. The FTO/TiO 2 /Au/Na+-doped MAPbI 3 construction with considerable photocurrent would be an alternative approach for light-to-electricity conversion. Image 1 • A novel IPHC device has been adopted to collect hot electrons under steady-state sunlight illumination. • The location of the perovskite active layer is on the utmost outside of the collection structure of Au/TiO 2 /FTO. • The performance of this newly developed hot electron collection device is enhanced by P-type doping the perovskite layer. • P-type doping is the effective way to boost the hot electron internal photoemission. [ABSTRACT FROM AUTHOR]