Abdelhamied Mostafa M, Song Yiling, Liu Weiwei, Li Xiaohong, Long Hua, Wang Kai, Wang Bing, Lu Peixiang
Wuhan National Laboratory for Optoelectronics and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, People's Republic of China. Radiation Physics Department, National Center for Radiation Research and Technology (NCRRT), Atomic Energy Authority (AEA), Cairo, Egypt.
Nanotechnology. 2020 Jun 30;31(42):42LT01. doi: 10.1088/1361-6528/aba140.
2D organic-inorganic lead iodide perovskites hold great promise for functional optoelectronic devices. However, their performances have been seriously limited by poor long-term stability in ambient environment. Here, we perform a systematic study for the stability improvement of a typical 2D organic-inorganic lead iodide perovskite (PEA)PbI. The degradation of the (PEA)PbI films can be attributed to the interaction with the humidity in environment, which leads to decomposition of the perovskite components. Then, we demonstrate that polymer passivation provides an effective approach for improving the crystal quality and stability of the (PEA)PbI films. Correspondingly, the photoemission of the polymer-passivated (PEA)PbI films has been enhanced due to the decreased trap states. More importantly, a hydrophobic polymer (Poly(4-Vinylpyridine), PVP) will protect the (PEA)PbI films from humidity in ambient environment, which can greatly improve the physical and chemical stability of the 2D perovskite films. As a result, the PVP-passivated (PEA)PbI films can produce a bright emission even after long-term (>15 d) exposure to ambient environment (25 °C, 80% RH) and continuous UV illumination. This work provides a convenient and effective approach for improving the long-term stability of 2D organic-inorganic lead iodide perovskites, which shows great promise for fabricating large-area and versatile optoelectronic devices.
二维有机-无机碘化铅钙钛矿在功能性光电器件方面极具潜力。然而，其性能在环境中由于长期稳定性差而受到严重限制。在此，我们对典型的二维有机-无机碘化铅钙钛矿（PEA）PbI的稳定性提升进行了系统研究。（PEA）PbI薄膜的降解可归因于与环境中湿度的相互作用，这导致钙钛矿成分分解。然后，我们证明聚合物钝化为提高（PEA）PbI薄膜的晶体质量和稳定性提供了一种有效方法。相应地，由于陷阱态减少，聚合物钝化的（PEA）PbI薄膜的光发射得到增强。更重要的是，一种疏水性聚合物（聚（4-乙烯基吡啶），PVP）将保护（PEA）PbI薄膜免受环境湿度影响，这可极大提高二维钙钛矿薄膜的物理和化学稳定性。结果，即使在长期（>15天）暴露于环境（25°C，80%相对湿度）和持续紫外光照后，PVP钝化的（PEA）PbI薄膜仍能产生明亮发射。这项工作为提高二维有机-无机碘化铅钙钛矿的长期稳定性提供了一种便捷有效的方法，这对于制造大面积和多功能光电器件具有巨大潜力。
