Dimensional Engineering of a Graded 3D-2D Halide Perovskite Interface Enables Ultrahigh V-oc Enhanced Stability in the p-i-n Photovoltaics

作者：Bai, Yang; Xiao, Shuang; Hu, Chen; Zhang, Teng; Meng, Xiangyue; Lin, He; Yang, Yinglong; Yang, Shihe^*

来源：Advanced Energy Materials, 2017, 7(20): 1701038.

DOI：10.1002/aenm.201701038

• blocking ion migration
• dimensional engineering
• energy level alignment
• enhanced stability
• reduced interfacial charge recombination

2D halide perovskite materials have shown great advantages in terms of stability when applied in a photovoltaic device. However, the impediment of charge transport within the layered structure drags down the device performance. Here for the first time, a 3D-2D (MAPbI(3)-PEA(2)Pb(2)I(4)) graded perovskite interface is demonstrated with synergistic advantages. In addition to the significantly improved ambient stability, this graded combination modifies the interface energy level in such a way that reduces interface charge recombination, leading to an ultrahigh V-oc at 1.17 V, a record for NiO-based p-i-n photovoltaic devices. Moreover, benefiting from the graded structure induced continuously upshifts energy level, the photovoltaic device attains a high Jsc of 21.80 mA cm(-2) and a high fill factor of 0.78, resulting in an overall power conversion efficiency (PCE) of 19.89%. More importantly, it is showed that such a graded interface structure also suppresses ion migration in the device, accounting for its significantly enhanced thermal stability.

• 出版日期2017-10-25