Induced Crystallization of Perovskites by a Perylene Underlayer for High-Performance Solar Cells
journal contributionposted on 29.04.2016, 00:00 by Zhao-Kui Wang, Xiu Gong, Meng Li, Yun Hu, Jin-Miao Wang, Heng Ma, Liang-Sheng Liao
Any type of content formally published in an academic journal, usually following a peer-review process.
Perovskite crystallization and interface engineering are regarded as the most crucial factors in achieving high-performance planar heterojunction (PHJ) perovskite solar cells (PSCs). Herein, we demonstrate a thin perylene underlayer via a solution-processable method. By using branch-shaped perylene film as a seed-mediated underlayer, crystalline perovskites with fabric morphology can be formed, which allows for obvious improvement in absorption by a light scattering effect. With its deep highest occupied molecular orbital (HOMO) level, perylene also plays an important role in the energy-level tailoring of poly(3,4-ethylenedioxythiophene): poly(styrenesulphonate) (PEDOT:PSS) and CH3NH3PbIxCl3–x. In addition, perylene and perovskites form a fully crystalline heterojunction, which is beneficial for minimizing the defect and trap densities. Due to these merits, a maximum power conversion efficiency of 17.06% with improved cell stability is achieved. The finding in this work provides a simple route to control perovskite crystallizaition and to optimize the interfaces in PHJ PSCs simultaneously.