Yellow light-emitting diodes (LEDs) are widely utilized in high-quality lighting, light communication, indicator lamps, etc. Owing to their outstanding material properties and device performance, the metal halide perovskites have demonstrated a significant potential for LED applications. However, the performance of the yellow perovskite LEDs (PeLEDs) is inferior to that of their green and red counterparts, with the maximum external quantum efficiency (EQE) limited to ∼3.1%. Further, a majority of the yellow PeLEDs are fabricated using the spin-coating methods. The current study reports the development of the yellow CsPbBr₂I PeLEDs based on an all-vacuum deposition approach, which has been widely employed in the commercial organic LEDs (OLEDs). By controlling the co-evaporation rate of CsI and PbBr₂, the growth kinetics of the perovskite layer are regulated to achieve a small grain size of ∼31.8 nm. Consequently, an improved radiative recombination rate (8.04 × 10⁻⁹ cm³/s) is obtained owing to the spatial confinement effect. The PeLEDs based on the optimal perovskite film demonstrate the yellow electroluminescence (574 nm) with a maximum EQE of ∼3.7% and luminance of ∼16,200 cd/m², thus, representing one of the most efficient and bright yellow PeLEDs. Overall, this study provides a useful guideline for realizing the efficient PeLEDs based on the thermal evaporation strategy and highlights the potential of PeLED as an efficient and bright yellow light source.

黄色发光二极管 (LED) 广泛应用于高品质照明、光通信、指示灯等。由于其出色的材料性能和器件性能，金属卤化物钙钛矿在 LED 应用中显示出巨大的潜力。然而，黄色钙钛矿 LED (PeLED) 的性能不如绿色和红色对应物，最大外量子效率 (EQE) 限制在 ~3.1%。此外，大多数黄色 PeLED 是使用旋涂方法制造的。目前的研究报告了基于全真空沉积方法的黄色 CsPbBr _{2 I PeLED 的开发，该方法已广泛应用于商业有机 LED (OLED)。}通过控制CsI和PbBr的共蒸发速率_如图2所示，调节钙钛矿层的生长动力学以实现约 31.8 nm 的小晶粒尺寸。因此，由于空间限制效应，获得了改进的辐射复合率（8.04 × 10 ^-9 cm ^{3 /s）。}基于最佳钙钛矿薄膜的 PeLED 表现出黄色电致发光 (574 nm)，最大 EQE 约为 3.7%，亮度约为 16,200 cd/m ²，因此是最高效、最亮的黄色 PeLED 之一。总的来说，这项研究为实现基于热蒸发策略的高效 PeLED 提供了有用的指导，并突出了 PeLED 作为高效明亮黄色光源的潜力。