The paper reports the analysis of (In)AlGaN-based UV-B LEDs degradation under constant current stress, and investigates the impact of defects in changing the devices electro-optical performance. The study is based on combined electro-optical characterization, deep-level transient- (DLTS) and photocurrent spectroscopy. UV-B LEDs show a decrease of the optical power during stress, more pronounced at low measuring current levels, indicating that the degradation is related to an increase of Shockley-Read-Hall (SRH) recombination. DLTS measurements allowed the identification of three defects, in particular one ascribed to Mg-related acceptor traps presence. Photocurrent spectroscopy allows the localization of the defects close to the mid-gap.

Date Published: 16 February 2017
PDF: 9 pages
Proc. SPIE 10124, Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XXI, 101240T (16 February 2017);

Published in SPIE Proceedings Vol. 10124:
Light-Emitting Diodes: Materials, Devices, and Applications for Solid State Lighting XXI
Jong Kyu Kim; Michael R. Krames; Li-Wei Tu; Martin Strassburg, Editor(s)