Interface contact optimization and defect passivation via tyramine hydrochloride for efficient and stable inverted perovskite solar cells

Abstract

Efficient and stable inverted perovskite solar cells (PSCs) have combined many advantages which makes them particularly promising, with potential for rapid commercialization. However, there are still some challenges to overcome, including poor energy level alignment between perovskite and charge transport interlayers, the presence of deleterious interface defects, and the hydrophobicity of NiO_x/PTAA-based double hole transport layer which seriously depress the improvement of the power conversion efficiency (PCE) and stability of PSCs. Presently, we utilized a passivating salt, tyramine hydrochloride (TACl), to modify the NiO_x/PTAA film and both perovskite absorber interfaces. The modification using TACl resulted in improving wettability of the PTAA film through the formation of cid-base interactions at solvation model and nonconventional -OH···π hydrogen bonds as well as optimizing energy level alignment, a lower rate of nonradiative recombination, and a markedly improved crystal quality of the perovskite films. Finally, we obtained a NiO_x/PTAA-based inverted PSCs device with a PCE of 23.35 %. Our unencapsulated optimized devices maintained 90.2 % of their initial PCE after 1000 h of MPPT monitoring. In addition, we prepared the PSCs devices with the bandgaps of 1.56 eV and 1.68 eV, which achieved PCEs of 25.13 % and 22.36 %, respectively.