表面等离激元修饰的ZnO核壳量子点发光特性及其短波长LED研究

Quantum dot light-emitting diode (QLED), as a new and promising luminescence technology in the future, is a research hot spot in the field of modern light emitters, owing to their high fluorescence efficiency, tunable luminescence wavelength and pure light-emitting color. So far, the research and development of high-performance semiconductor QLEDs with UV light emission have always been a difficult challenge. ZnO was recognized as one of the most important wide-band-gap semiconductor materials after the success of GaN. This proposal aims to explore and develop QLEDs with high-efficiency short-wavelength emission based on ZnO core/shell structured quantum dots (QDs). In this project, a new QLED device structure is proposed, in which single-crystalline ZnO QDs as active emission layer, core/shell quantum-well energy band alignment and surface plasmons (SPs) have been synergistically introduced. To compensate the mobility difference between electron and hole, an ultrathin amorphous oxide film, serving as electron retarding/blocking layer, is properly inserted into the QLED device structure, which facilitates effective radiative recombination of injected electrons and holes within the ZnO QDs active region. Furthermore, metal-based or carbon-based SPs with low joule dissipation and wide spectral resonance range, are also employed for enhancing the UV electroluminescence performance of these ZnO core/shell structured QLEDs, by means of the resonance coupling effect between SPs and excitons. This proposal focuses on the application demand of short-wavelength QLEDs, and suggests a novel plan for developing ZnO-based high-efficiency UV QLEDs. The research findings of this project may provide scientific and technical references for developing light-emitting devices based on other wide-band-gap semiconductors. All in all, this proposal is a cutting-edge research project in multidiscipline fields such as physics, information science and optoelectronics.

量子点发光二极管（QLED）具有高光效、可调谐、颜色纯等优点，是未来极具潜力的发光技术，是当前发光器件领域内的研究热点。目前，高性能紫外波段QLED的研发是该领域的难点和亟待突破的方向。ZnO是继GaN之后一种重要的第三代半导体材料。本项目拟开展基于ZnO核壳量子点的短波长QLED研究：提出将单晶ZnO量子点、核壳量子阱、表面等离激元（SP）三位一体地引入到QLED中这一结构设计新思路；在器件中插入超薄非晶氧化物电子阻滞层，平衡电子和空穴在迁移率上的差异，促进载流子在ZnO量子点层辐射复合；利用低损耗、宽带可调的金属SP或新型碳基SP与ZnO量子点进行共振耦合，进一步提升ZnO基QLED的紫外发光性能。本项目聚焦短波长QLED的应用需求，提出了发展ZnO基高效紫外光QLED的新方案，并为研发基于其它宽禁带材料的发光器件提供参考，是物理、信息和光电子学交叉领域的前沿课题。

自2019年项目执行以来，负责人严格按照任务书中的研究计划开展相关工作，以低维ZnO材料的器件化和功能化为导向，针对领域内的关键科学问题，开展了高质量ZnO量子点材料的大规模绿色合成，光学/电学性能调控，低维ZnO基等离激元增强型发光器件，以及新型低维无机激子半导体发光物理和载流子动力学调控等方面的研究工作。相关研究获得了基于ZnO核壳量子点复合体系有源层的高效紫外发光QLED器件，实现了对该复合体系的光学、电学性质的可控调节，阐明了该复合器件紫外光发射增强的物理机制。.研究结果以第一作者/通讯作者身份发表于Laser & Photonics Reviews、Nano Letters、Nano Energy、Materials Horizons 等SCI检索期刊23篇；申报国家发明专利5项，授权2项；受邀参与撰写《Phosphor Handbook》（第3版）等英文专著2部；作为负责人获批国家自然科学基金面上项目，吉林省重点项目等多个课题资助；作为项目骨干参与国家重点研发计划等课题研究；多次在国际/国内学术会议上作邀请报告，获第19届国际发光会青年学者奖；培养/协助培养博士毕业生2名，硕士毕业生9名。