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. 2018 Sep 26;10(38):32289-32297. doi: 10.1021/acsami.8b07048. Epub 2018 Sep 17.
In this study, a dual-source vapor evaporation method was employed to fabricate the high-quality CsPbBr thin films with a good crystalline and high surface coverage. Temperature-dependent and excitation power-dependent photoluminescence measurements were performed to study the optical properties of the CsPbBr material. Further, based on the experimental data, the temperature sensitivity coefficient of band gap and exciton binding energy were estimated. More importantly, for the first time, we designed and prepared a hole-injection layer-free perovskite light-emitting diode (LED) based on the Au/MgO/CsPbBr/n-MgZnO/n-GaN structure, producing an intense green emission (∼538 nm) with a high purity. Besides, the device demonstrated a high luminance of 5025 cd/m, an external quantum efficiency of 1.46%, a current efficiency of 1.92 cd/A, and a power efficiency of 1.76 lm/W. We studied in detail the current-voltage and electroluminescence properties of the prepared device and proposed the hole generation models and the carrier transport/recombination mechanisms to make these interesting characteristics certain. The results obtained would provide a new and effective strategy for the design and preparation of perovskite LEDs.
在这项研究中，采用双源蒸汽蒸发法制备了高质量的 CsPbBr 薄膜，具有良好的结晶性和高表面覆盖率。进行了温度依赖和激发功率依赖的光致发光测量，以研究 CsPbBr 材料的光学性质。此外，基于实验数据，估计了带隙和激子结合能的温度灵敏度系数。更重要的是，我们首次设计并制备了基于 Au/MgO/CsPbBr/n-MgZnO/n-GaN 结构的无空穴注入层钙钛矿发光二极管（LED），产生了高强度的绿光发射（∼538nm），纯度高。此外，该器件的亮度高达 5025 cd/m，外量子效率为 1.46%，电流效率为 1.92 cd/A，功率效率为 1.76 lm/W。我们详细研究了制备器件的电流-电压和电致发光特性，并提出了空穴产生模型和载流子输运/复合机制，以确定这些有趣的特性。所获得的结果将为钙钛矿 LED 的设计和制备提供新的有效策略。
