通过后处理诱导的相调控增强铯铜卤化物纳米晶发光二极管性能

Enhanced performance of cesium copper halide nanocrystal light-emitting diodes via post-treatment induced phase regulation

铯铜卤化物由于其高光致发光量子效率(PLQE)和无毒性而引起了越来越多的关注,适用于发光二极管(LED)应用。然而,目前的铜卤化物薄膜制备方法无法同时满足高性能、环保和良好环境适应性的要求。在这里,我们展示了一种简便的方法,其结合了传统的纳米晶方法和前驱体溶液方法的优点。通过使用适当的醇处理Cs_(3)Cu_(2)I_(5)纳米晶薄膜,形成了具有增强的PLQE和改善的能级匹配性的Cs_(3)Cu_(2)I_(5)/CsCu_(2)I_(3)混合维度铜卤化物,将铜卤化物LED的EQE提高到0.8%,处于无铅金属卤化物纳米晶LED的最高效率之一。这项工作为以环境友好方式制备高性能无铅LED提供了新的策略。

Cesium copper halides have attracted increasing attention for light-emitting diodes(LEDs)applications due to their high photoluminescence quantum efficiency(PLQE)and non-toxicity.However,the current film fabrication methods for copper halides cannot simultaneously meet the high-performance,eco-friendly,and good environmental tolerance requirements.Here,we demonstrate a facile approach that combines the advantages of both traditional nanocrystal-based methods and precursor solution-based methods.Through treating Cs_(3)Cu_(2)I_(5)nanocrystal films with proper alcohols,Cs_(3)Cu_(2)I_(5)/CsCu_(2)I_(3)mixed-dimensional copper halides are formed with enhanced PLQE and improved energy level matching.This enhances the peak EQE of copper halide LEDs to 0.8%,which is among the highest efficiency of lead-free metal halide nanocrystal LEDs.This work provides a new strategy for fabricating highperformance lead-free LEDs in an eco-friendly manner.