Yeh Kuan-Chi, Chan Chia-Hua
Graduate Institute of Energy Engineering, National Central University, No. 300, Zhongda Rd., Zhongli Dist., Taoyuan City, 32001, Taiwan, ROC.
Sci Rep. 2024 Feb 9;14(1):3351. doi: 10.1038/s41598-024-54036-6.
In this work, we utilized CsPbBr powder as the precursor material for the single-source vapor deposition (SSVD) process to fabricate the CsPbBr emitting layer. Due to the high density of grain boundaries and defects in the thin films deposited in the initial stages, non-radiative recombination can occur, reducing the efficiency of perovskite light-emitting diodes (PeLED). To address this issue, we employed a thermal annealing process by subjecting the perovskite films to the appropriate annealing temperature, facilitating the coalescence and growth of different grains, improving lattice integrity, and thereby reducing the presence of defects and enhancing the photoluminescence performance of the films. Furthermore, in this study, we successfully fabricated simple-structured CsPbBr PeLED using thermally annealed CsPbBr films. Among these components, even without adding the electron and hole transport layers, the best-performing device achieved a maximum brightness of 14,079 cd/m at a driving voltage of only 2.92 V after annealing at 350 °C; the brightness is 16.8 times higher than that of CsPbBr PeLED without heat treatment, demonstrating outstanding light-emitting performance. The research results show that using SSVD to prepare CsPbBr PeLED has broad application potential, providing a simple process option for research on improving the performance of PeLED.
在本工作中，我们使用CsPbBr粉末作为单源气相沉积（SSVD）工艺的前驱体材料来制备CsPbBr发光层。由于在初始阶段沉积的薄膜中存在高密度的晶界和缺陷，可能会发生非辐射复合，从而降低钙钛矿发光二极管（PeLED）的效率。为了解决这个问题，我们采用了热退火工艺，将钙钛矿薄膜置于适当的退火温度下，促进不同晶粒的聚结和生长，改善晶格完整性，从而减少缺陷的存在并提高薄膜的光致发光性能。此外，在本研究中，我们使用经过热退火的CsPbBr薄膜成功制备了结构简单的CsPbBr PeLED。在这些组件中，即使不添加电子和空穴传输层，性能最佳的器件在350℃退火后，在仅2.92V的驱动电压下实现了14,079 cd/m的最大亮度；该亮度比未经热处理的CsPbBr PeLED高16.8倍，展现出出色的发光性能。研究结果表明，使用SSVD制备CsPbBr PeLED具有广阔的应用潜力，为改善PeLED性能的研究提供了一种简单的工艺选择。
