Highly efficient GaN-based cascaded LEDs

高效 GaN 基级联 LED

• 批准号: 447864265
• 负责人: Dr. Christoph Berger
• 金额: --
• 依托单位: Abteilung Halbleiterepitaxie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2020
• 资助国家: 德国
• 起止时间: 2019-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/447864265?language=en
• 关键词: Highly; efficient; GaN; based; cascaded

The aim of the project is the development of GaN-based cascaded LEDs. Thereby, several pn junctions are connected in series by using transparent tunnel junctions. In contrast to conventional LEDs, which show a drastical reduction of the efficiency at high current densities, cascaded LEDs have the potential to achieve high conversion efficiencies even at high electrical input powers, since high-power devices are operated at high voltage and and low current-density at the same time. Thus, the number of electrons and holes injected is not increased for higher brightness, but only the number of photons generated.The cascaded LEDs will be manufactured by using the only industrially relevant process of metalorganic vapor phase epitaxy in a monolithic process. A main focus is on the optimization of the doping profiles and an efficient activation of the buried GaN:Mg layers in order to ensure a minimal voltage penalty at the tunnel junctions. The project aims to increase the light output by more than 90 % per additional pn transition, while the operating voltage increases by less than 4 V. Ultimately, we aim to realize a cascaded LED with an operating voltage of 12 V and an input power of 2.4 W, which has a 70 % higher optical output power and an at least 350 % higher external quantum efficiency compared to a conventional LED.

该项目的目标是GaN基级联LED的开发。由此，通过使用透明隧道结将若干pn结串联连接。与在高电流密度下显示出效率的显著降低的常规LED相比，级联LED具有甚至在高电输入功率下实现高转换效率的潜力，因为高功率器件同时在高电压和低电流密度下操作。因此，注入的电子和空穴的数量不会增加以获得更高的亮度，而只是增加产生的光子的数量。一个主要的重点是优化的掺杂分布和有效的激活的掩埋GaN：Mg层，以确保在隧道结的电压惩罚最小。该项目旨在每增加一个pn跃迁，光输出增加90%以上，而工作电压增加不到4 V，最终我们的目标是实现工作电压为12 V，输入功率为2. 4 W的级联LED，其具有比常规LED高70%的光输出功率和高至少350%的外部量子效率。