Key Laboratory of Materials Physics of Ministry of Education, Department of Physics and Engineering, Zhengzhou University , Daxue Road 75, Zhengzhou 450052, China.
State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University , Qianjin Street 2699, Changchun 130012, China.
ACS Appl Mater Interfaces. 2017 Dec 13;9(49):42893-42904. doi: 10.1021/acsami.7b13260. Epub 2017 Nov 28.
The vapor-assisted solution method was developed to prepare high-quality organic-inorganic halide perovskite CHNHPbBr (MAPbBr) thin films. We detailedly investigated the effect of evaporation time and temperature of MABr powder on the microstructure, crystallinity, and optical characterizations of MAPbBr thin films, and a controllable morphology evolution with varying surface coverage was observed. Temperature-dependent and time-resolved photoluminescence measurements were carried out to investigate the optical transition mechanisms and carrier recombination dynamics of MAPbBr thin films. Our results revealed that no structural phase transition occurred within the heating process (10-300 K). In addition to the exciton-related emission, a trapped charge-carrier emission appeared at a critical temperature of 140 K. The corresponding temperature sensitivity coefficient of band gap, exciton binding energy, and optical phonon energy of the MAPbBr thin films were extracted from the experimental data. Furthermore, planar perovskite light-emitting diodes (PeLEDs) based on a Al/LiF/TPBi/MAPbBr/NiO/ITO structure were fabricated, and a high-purity green emission at ∼532 nm with a low line width (25 nm) was achieved. The devices demonstrated remarkable performances with high luminance (6530 cd/m), current efficiency (8.16 cd/A), external quantum efficiency (4.36%), and power efficiency (4.49 lm/W). This research will provide valuable information for the preparation of high-quality perovskite thin films, facilitating their future applications in novel high-performance PeLEDs.
蒸气辅助溶液法被开发出来以制备高质量的有机-无机卤化物钙钛矿 CHNHPbBr（MAPbBr）薄膜。我们详细研究了 MABr 粉末的蒸发时间和温度对 MAPbBr 薄膜的微观结构、结晶度和光学特性的影响，观察到了具有不同表面覆盖率的可控形貌演变。进行了温度依赖和时间分辨光致发光测量，以研究 MAPbBr 薄膜的光学跃迁机制和载流子复合动力学。我们的结果表明，在加热过程（10-300 K）中没有发生结构相变。除了激子相关的发射之外，在 140 K 的临界温度下出现了被捕获的电荷载流子发射。从实验数据中提取了 MAPbBr 薄膜的带隙、激子结合能和光学声子能量的相应温度灵敏度系数。此外，基于 Al/LiF/TPBi/MAPbBr/NiO/ITO 结构的平面钙钛矿发光二极管（PeLED）被制备，实现了 ∼532nm 的高纯度绿色发射，线宽低（25nm）。该器件表现出出色的性能，具有高亮度（6530 cd/m）、电流效率（8.16 cd/A）、外量子效率（4.36%）和功率效率（4.49 lm/W）。这项研究将为制备高质量的钙钛矿薄膜提供有价值的信息，促进其在新型高性能 PeLED 中的未来应用。
