Portal de Periódicos da CAPES

AlGaN-based deep ultraviolet micro-LED emitting at 275 nm

2021; Optica Publishing Group; Volume: 46; Issue: 13 Linguagem: Inglês

10.1364/ol.431933

1539-4794

Huabin Yu, Muhammad Hunain Memon, Danhao Wang, Zhongjie Ren, Haochen Zhang, Chen Huang, Meng Tian, Haiding Sun, Shibing Long,

ZnO doping and properties

The investigation of electrical and optical properties of micro-scale AlGaN deep ultraviolet (DUV) light-emitting diodes (LEDs) emitting at ∼ 275 n m was carried out, with an emphasis on fabricated devices having a diameter of 300, 200, 100, 50, and 20 µm, respectively. It was revealed that the LED chips with smaller mesa areas deliver considerably higher light output power density; meanwhile, they can sustain a higher current density, which is mainly attributed to the enhanced current spreading uniformity in micro-scale chips. Importantly, when the diameter of LED chips decreases from 300 µm to 20 µm, the peak external quantum efficiency (EQE) increases by 20%, and the EQE peak current density can be boosted from 8.85 A / c m 2 and 99.52 A / c m 2 . Moreover, we observed a longer wavelength emission with enlarged full-width at half-maximum (FWHM) in the LEDs with smaller chip sizes because of the self-heating effect at high current injection. These experimental observations provide insights into the design and fabrication of high-efficiency micro-LEDs emitting in the DUV regime with different device geometries for various future applications.