ZnO发光二极管研制与发光效率提升机制研究

本项目针对ZnO发光二极管（LED）研制和发光效率提升机制，采用MOCVD、MBE方法制备Na掺杂ZnO单晶薄膜；同时引入合适元素(Mg等)对能带结构、Na受主能级、近邻配位和局部应变进行调控，抑制本征施主补偿、降低受主能级、提高受主掺杂量和稳定性；并采用辅助掺杂剂H提高Na受主替代比，进一步提高空穴浓度和p型稳定性。通过优化工艺实现界面原子级精控，外延生长高质量ZnO/ZnMgO多量子阱；通过多量子阱组分和带阶设计，高效限制载流子，提高发光内量子效率。设计合适LED结构、多层金属p型欧姆接触，构筑注入和出光效率一致优化ZnO-LED芯片体系。本项目从ZnO基薄膜生长、p型掺杂技术（包括钠MO源）、能带调控到LED器件结构设计及制备，整个流程都具有自主知识产权，为今后深入研究和产业化奠定基础。该项目研究为面向能源半导体节能白光照明技术发展提供新材料和新器件体系，具有重要科学意义和实用价值。

In this project, we highlight the fabrication of ZnO-based LED and mechanism of advancing its luminescence efficiency. Na doping is developed to explore p-type ZnO single crystalline films via MOCVD and MBE technique. Specifically elements, such as Mg etc., are proposed to weaken the compensation of intrinsic donors, and reduce the energy level of Na acceptor. And assistant dopant H is introduced to play an important role in restraining interstitial dopants. P-type doping with high hole concentration and high stability is expected be achieved in this project. The studies on advancing luminescence efficiency of ZnO-LED will be concentrated on the preparation and structural designing of high quality ZnO/ZnMgO quantum wells with atomic-level controlled interfaces. The carriers will be high efficiently confined and high luminescence efficiency can be foreseen. High efficient LED fabrication packages the optimized LED structures and p-type ohmic contact using multilayer metals. We aim at obtaining high inject efficiency and high outer luminescence efficiency simultaneously. In this project, we will develop independently the preparation of ZnO-based single crystalline films, p-type doping strategies (including exploring metal-organic sodium source), bandgap engineering, even the p-type ohmic contact and LED structures. Our strategy will not only pave the way for further research and industrialization of ZnO-based devices, but be highly significant to novel materials and devices oriented to energy saving white light illumination.