紫外LED研究进展

 氮化物紫外LED的发光波长覆盖210~400 nm的紫外波段，可广泛应用于工业、环境、医疗和生化探测等领域。近年来紫外LED的技术水平发展迅速，器件性能不断提升。由于高Al组分AlGaN材料的固有特性，目前深紫外LED的外量子效率和功率效率仍有大量提升空间。综述了近年来AlGaN基紫外LED的研究进展，阐述了限制其性能的AlGaN外延质量、高Al组分AlGaN材料的掺杂效率、紫外LED量子结构、紫外LED光提取效率及可靠性等核心难题以及取得的重要研究进展。预计到2025年，深紫外LED的量产单芯片光输出功率可突破瓦级，功率效率有望提升至20%以上，寿命达到万小时级别。

Recent progress of ultraviolet light-emitting diodes

The III-nitride based ultraviolet light-emitting diodes (UV LEDs) have tunable emission wavelengths covering a range from 210nm to 400nm, making them suited to be applied in many fields, such as industrial, environmental, medical and biochemical detection fields. Rapid great technical breakthroughs have been made to improve the performance of the AlGaN UV LEDs over the past few years. However, there is still much room for the improvement of the external quantum efficiency and the wall plug efficiency of the deep-UV LEDs due to the intrinsic properties of the Al-rich AlGaN materials. This paper reviews the recent development of the AlGaN UV LEDs, as well as the key challenges to the efficiency improvement, including the epitaxy quality, the doping efficiency, the quantum structure, the light extraction and the reliability, and the effective solutions. It is estimated that by the year 2025, the single-chip light output power of the deep-UV LED will exceed the watt level, the wall plug efficiency is expected to be increased to over 20%, and the lifetime will reach a level of 10⁴ hours.