基于金纳米粒子修饰空穴注入层的高效率钙钛矿发光二极管  

Highly efficient PeLEDs using gold nanoparticles modified PEDOT:PSS as the hole injection layer

作　　者：熊自阳 吴小龑 高春红[1] 林春燕 熊祖洪[1] 陈平[1] 

机构地区：[1]西南大学物理科学与技术学院,发光与实时分析教育部重点实验室,重庆400715 [2]中国工程物理研究院流体物理研究所,绵阳621900 [3]西南大学材料与能源学部,重庆市洁净能源与先进材料研究院,重庆400715

出　　处：《科学通报》2017年第32期3774-3782,共9页Chinese Science Bulletin

基　　金：国家自然科学基金(61404108,11504300,11374242);国家自然科学基金委员会/中国工程物理研究院联合基金(U1630125);重庆市基础与前沿研究计划(cstc2015jcyj A50002);中央高校基本业务费专项资金(XDJK2017D140)资助

摘　　要：有机-无机杂化钙钛矿电致发光器件(Pe LEDs)在平板照明和显示等方面有着重要应用前景,并且具有成本低和制备过程简单等优点,近年来吸引了越来越多科学家的关注和研究.如何通过优化器件结构,进一步提高Pe LEDs的电致发光效率及发光的稳定性是当前的研究热点.在优化光电器件性能上,金纳米粒子(Au NPs)以其特殊的小尺寸效应提供了诸多材料没有的特殊优势.本文以Frens法制备了粒径为~20 nm的水溶性Au NPs,然后以一定体积比加入到空穴注入层Poly(3,4-Ethylene Dioxythiophene):Poly(Styrene Sulfonate)(PEDOT:PSS)中,制备成AuNPs修饰的Pe LEDs.实验结果发现,加入Au NPs后,CH_3NH_3PbBr_3钙钛矿薄膜的光致发光性能和电致发光性能都得到了显著的提高,分别为原先的~2.41倍和~1.48倍.其中,Au NPs修饰的PeLEDs的启亮电压为~3.0 V,最大亮度为~16050 cd/m^2,最高电流效率为~7.02 cd/A.机理研究表明,AuNPs的表面等离子体局域共振吸收谱与发光层CH3NH3Pb Br3的荧光发射谱重叠得很好,因此Au NPs能加快PEDOT:PSS/CH_3NH_3PbBr_3界面处激子的发光辐射退激速率,从而减少了该界面处的激子被附近的剩余载流子(空穴)淬灭的数量,使界面处更多的激子被用来发光,从而提高了激子的利用率.本文提出了一种通过Au NPs界面修饰来提高Pe LEDs发光效率的有效途径,这对于Au NPs表面等离子体共振的基础研究以及改善Pe LEDs的发光效率都具有非常重要的意义.Organic-inorganic hybrid perovskite light-emitting diodes（Pe LEDs） have attracted increasing attentions recently due to their great potential in flat panel display and lightening as well as other advantages such as low cost, ease of fabrication, high color purity, and tunable emission from the visible to infrared wavelengths. Improving the electroluminescent efficiency and the device stability of Pe LEDs became hot spots in recent studies. To achieve highly efficient Pe LEDs, two critical criteria must be satisfied： pinhole-free perovskite film to suppress leakage currents and optimized device structures with minimum injection barriers that guarantee balanced charge injection into perovskites. Over the last decades, metallic nanostructures have been focused on improving the efficiency of organic optoelectronic devices, which is mainly based on the optical and electrical effects of metal nanoparticles（NPs）, including localized surface plasmon resonance（LSPR）-enhanced fluorescence, electrical properties, interface effect, light scattering, and so on. However, there is few research dedicated to the metal plasmonic enhanced electroluminescence of perovskite. Driven by this motivation, metal NPs may provide many advantages in improving the performance of Pe LEDs through optimizing the device structure. In this work, gold nanoparticles（Au NPs） aqueous solution（with Au NPs diameter of -20 nm） was first synthesized by ＂Frens＂ method. And then, the Au NPs modified poly（3,4-ethylene dioxythiophene）：poly（styrene sulfonate）（PEDOT：PSS）, which was obtained by mixing Au NPs aqueous solution with PEDOT：PSS with a desired volume ratio of 0.2：1, was introduced into CH3NH3PbBr3-based Pe LEDs as the hole injection layer. It should be noted that the -20 nm Au NPs was fully covered by -45 nm PEDOT：PSS layer in order to avoid direct contact with the active layer of CH3NH3PbBr3, which is critical to prevent excitions quenching by a nonradiative energy transfer process at the surfaces of th

关 键 词：金纳米粒子 空穴注入层 高效率 钙钛矿发光二极管 

分 类 号：TN312.8[电子电信—物理电子学]