High-Performance CsPbI₂Br Perovskite Solar Cells with Zinc and Manganese Doping

Photovoltaic performances of CsPbI₂Br solar cells are still lower than those of hybrid inorganic-organic perovskite solar cells, and researchers are exploring ways to improve their efficiencies. Due to its higher thermal stability in comparison with the generally studied hybrid inorganic-organic perovskites, all-inorganic CsPbI₂Br has recently attracted great attention. By utilizing the combination of MnCl₂ and ZnCl₂ particles doping to modulate film growth, it is found that MnCl₂ and ZnCl₂ particles infiltrate into the holes of the CsPbI₂Br lattice through the growth procedure, leading to suppressed nucleation and reduced growth rate. The combination assists to achieve higher CsPbI₂Br crystalline grains for increased J_sc as high as 15.66 mA cm^-2 and FF as large as 73.37%. It is indicated that a specific combination of ZnCl₂-MnCl₂ doping can fundamentally improve the film surface morphology, reduce trap density, and suppress the recombination of carriers. Consequently, power conversion efficiency (PCE) is significantly improved from 13.47 to 14.15% compared with the reference device without doping.