Degradation behavior of deep UV-LEDs studied by electro-optical methods and transmission electron microscopy

• Published in: Current applied physics Vol. 19; no. 1; pp. 20 - 24
• Main Authors: Xiu, Huixin, Zhang, Yang, Fu, Jiajia, Ma, Zhanhong, Zhao, Lixia, Feng, Jijun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2019; 한국물리학회
• Subjects: Aging; AlGaN; Current leakage; Deep UV-LEDs; Degradation; 물리학; Degradation; Aging; Deep UV-LEDs; Current leakage; AlGaN
• ISSN: 1567-1739; 1878-1675
• DOI: 10.1016/j.cap.2018.10.019

Degradation mechanism of 265-nm deep ultraviolet light emitting diodes (UV-LEDs) has been investigated by means of electroluminescence, current-voltage measurement, capacitance-voltage measurement, and transmission electron microscopy (TEM) equipped with energy dispersive X-ray spectrometer (EDAX). It is revealed that a major degradation mode of UV-LEDs may be the leakage current induced optical degradation. The current pathway is demonstrated by TEM with EDAX, indicating that the contact metals can partially interact with p-type materials, which accelerate the degradation of LEDs. The presented results can help to understand the degradation mechanisms and improve the reliability of deep UV-LEDs. •Degradation of UV-LEDs are studied by electroluminescence, TEM, current-voltage and capacitance-voltage measurement.•A major degradation mode of UV LEDs is revealed as leakage current induced optical degradation.•Possible leakage pathways are identified by TEM with EDAX, providing evidence for the leakage current increase after aging.