Anion Confinement for Homogenous Mixed Halide Perovskite Film Growth by Electrospray.

Wide-bandgap perovskites are promising absorbers for state-of-the-art tandem solar cells to feasibly surpass Shockley-Queisser limit with low cost. However, the commonly used mixed halide perovskites suffer from poor stability, particularly, photoinduced phase segregation. Electrospray deposition is developed to bridge the gap of growth rate between iodide and bromide components during film growth by spatially confining the anion diffusion and eliminating the kinetic difference, which universally improves the initial homogeneity of perovskite films regardless of device architectures. It thus promotes the efficiency and stability of corresponding solar cells based on wide-band gap (1.68 eV) absorbers. Remarkable power conversion efficiency (PCE) of 21.44% and 20.77% are achieved in 0.08 cm2 and 1.0 cm2 devices, respectively. And these devices maintained 90% of their initial PCE after 1550 h of stabilized power output (SPO) tracking upon 1 Sun irradiation (LED) at room temperature. This article is protected by copyright. All rights reserved.