Zhao Lianfeng, Roh Kwangdong, Kacmoli Sara, Al Kurdi Khaled, Jhulki Samik, Barlow Stephen, Marder Seth R, Gmachl Claire, Rand Barry P
Department of Electrical Engineering, Princeton University, Princeton, NJ, 08544, USA.
School of Chemistry and Biochemistry, Center for Organic Electronics, Georgia Institute of Technology, Atlanta, GA, 30332-0400, USA.
Adv Mater. 2020 Jun;32(25):e2000752. doi: 10.1002/adma.202000752. Epub 2020 May 14.
The performance of lead-halide perovskite light-emitting diodes (LEDs) has increased rapidly in recent years. However, most reports feature devices operated at relatively small current densities (<500 mA cm ) with moderate radiance (<400 W sr m ). Here, Joule heating and inefficient thermal dissipation are shown to be major obstacles toward high radiance and long lifetime. Several thermal management strategies are proposed in this work, such as doping charge-transport layers, optimizing device geometry, and attaching heat spreaders and sinks. Combining these strategies, high-performance perovskite LEDs are demonstrated with maximum radiance of 2555 W sr m , peak external quantum efficiency (EQE) of 17%, considerably reduced EQE roll-off (EQE > 10% to current densities as high as 2000 mA cm ), and tenfold increase in operational lifetime (when driven at 100 mA cm ). Furthermore, with proper thermal management, a maximum current density of 2.5 kA cm and an EQE of ≈1% at 1 kA cm are shown using electrical pulses, which represents an important milestone toward electrically driven perovskite lasers.
近年来,铅卤化物钙钛矿发光二极管(LED)的性能迅速提升。然而,大多数报告中的器件是在相对较小的电流密度(<500 mA cm²)和中等辐射度(<400 W sr⁻¹ m⁻²)下运行的。在此,焦耳热和低效的热耗散被证明是实现高辐射度和长寿命的主要障碍。这项工作提出了几种热管理策略,例如掺杂电荷传输层、优化器件几何结构以及附加散热片和散热器。结合这些策略,展示了高性能的钙钛矿LED,其最大辐射度为2555 W sr⁻¹ m⁻²,峰值外量子效率(EQE)为17%,EQE滚降显著降低(在高达2000 mA cm²的电流密度下EQE > 10%),并且工作寿命增加了十倍(在100 mA cm²驱动时)。此外,通过适当的热管理,使用电脉冲在1 kA cm²时显示出最大电流密度为2.5 kA cm²和EQE约为1%,这代表了朝着电驱动钙钛矿激光器迈出的重要里程碑。