混合反溶剂法制备CsCu_(2)I_(3)纳米晶薄膜及其发光器件应用  

Synthesis of CsCu_(2)I_(3)Nanocrystalline Films by Mixed Antisolvent Strategy for Light-emitting Diodes

作　　者：姬心震 马壮壮 田世超 贾陌尘 陈旭[1] 史志锋[1] JI Xinzhen;MA Zhuangzhuang;TIAN Shichao;JIA Mochen;CHEN Xu;SHI Zhifeng(Key Laboratory of Materials Physics of Ministry of Education,School of Physics and Microelectronics,Zhengzhou University,Zhengzhou 450052,China;Henan Chaowei Photoelectric Technology Co.LTD,Zhengzhou 450001,China)

机构地区：[1]郑州大学物理学院材料物理教育部重点实验室,河南郑州450052 [2]河南超威光电科技有限公司,河南郑州450001

出　　处：《发光学报》2023年第3期559-568,共10页Chinese Journal of Luminescence

基　　金：国家自然科学基金(12074347,61935009)。

摘　　要：近年来,新兴的三元铜基卤化物(CsCu_(2)I_(3))材料由于具有高荧光量子产率、环保无毒、环境稳定、成本低廉等诸多优点,在环保型发光二极管(LED)中的应用备受瞩目。然而,由于难以控制的结晶动力学,制备高质量的CsCu_(2)I_(3)发光层薄膜仍是一个巨大的挑战,这限制了LED器件性能的进一步提升。本文通过使用甲苯与甲醇混合溶剂作为反溶剂来增强反溶剂的钉扎效应,增加CsCu_(2)I_(3)晶体的成核密度,降低薄膜的晶粒尺寸,进而形成了光滑、致密的CsCu_(2)I_(3)纳米晶薄膜。此外,混合反溶剂策略可以有效增强辐射复合效率,显著提高Cs-Cu_(2)I_(3)薄膜的发光性能,相比对照样品(只使用甲苯),混合反溶剂法所制备薄膜的荧光量子产率(PLQY)增加了1.5倍,激子束缚能从~201.6 meV提高至~234.5 meV。最终,相比对照器件,基于混合反溶剂策略的CsCu_(2)I_(3)基LED的最大亮度和最高外量子效率分别提高了5.5倍和1.6倍。本工作的研究结果不仅有助于加深对CsCu_(2)I_(3)薄膜制备过程中结晶规律的理解,而且有助于进一步推动基于CsCu_(2)I_(3)环境友好型LED器件性能的提升。Recently,the emerging ternary copper-based halide(CsCu_(2)I_(3))materials have attracted much attention in the application of environmentally friendly light-emitting diodes(LEDs)due to their high photoluminescence quantum yield(PLQY),non-toxicity,good stability,and low cost.However,the synthesis of high-quality CsCu_(2)I_(3)lightemitting films is still a great challenge due to the ungovernable crystallization dynamics of the CsCu_(2)I_(3),which limits the further improvement of device performance.Here,by using a mixed solvent of toluene and methanol as an antisolvent to improve the pinning effect from the antisolvent,increasing the nucleation density of CsCu_(2)I_(3)crystals,and reducing the grain size of the films,a smooth and dense CsCu_(2)I_(3)nanocrystalline film was formed.Moreover,the mixed antisolvent strategy can effectively enhance the radiative recombination efficiency and significantly improve the PL properties of the CsCu_(2)I_(3)films.Compared with the control sample(only using toluene),the PLQY of the films prepared by the mixed antisolvent method is increased by 1.5 times,and the exciton binding energy was increased from~201.6 meV to~234.5 meV.Finally,the maximum luminance and the external quantum efficiency of the CsCu_(2)I_(3)LED based on the mixed antisolvent strategy were enhanced by 5.5 times and 1.6 times compared with the control device,respectively.The results of this work are not only conducive to deepening the understanding of crystallization laws during the preparation of CsCu_(2)I_(3)films,but also help to further promote the device performance of CsCu_(2)I_(3)-based environmentally friendly LEDs.

关 键 词：CsCu_(2)I_(3) 纳米晶薄膜 反溶剂 黄光LED 

分 类 号：O482.31[理学—固体物理]