Reducing p-Doping of Tin Halide Perovskites by Trivalent Cation Doping

We investigate trivalent doping of tin halide perovskites as a means to decrease p-doping and control defect activity. Through density functional theory calculations and experimental characterization, we demonstrate that doping with scandium, lanthanum, and cerium successfully accomplishes Fermi level upshift, reducing background carrier concentration and defect densities, thereby improving material performance. Solar cell fabrication and testing highlight the doping efficacy, with lanthanum delivering increased photocurrent and open circuit voltage compared to control devices, despite being nonoptimized. This research underscores the potential of cation doping in enhancing the functionality of p-doped tin perovskites for advanced optoelectronic applications.