Progress in External Quantum Efficiency for Ⅲ-Nitride Based Deep Ultraviolet Light-Emitting Diodes

摘要

AlGaNbased deep ultraviolet lightemitting diodes (DUV LEDs) are featured with small size, DC driving, no environmental contamination etc., and they are now emerging as the excellent solidstate light source to replace the conventional mercury based light tubes. Nevertheless, the DUV LEDs are currently affected by the poor external quantum efficiency (EQE), which is caused by the low internal quantum efficiency (IQE) and the very unsatisfying light extraction efficiency (LEE). In this work, the authors disclose the underlying mechanism for the low EQE and summarize the technologies that have been adopted so far for enhancing the EQE.