340 nm-band high-power InAlGaN quantum well ultraviolet light-emitting diode using p-type InAlGaN layers

摘要

In order to achieve high-efficiency ultraviolet (UV) light-emitting diodes (LEDs), p-type layers with sufficient hole concentration is quite important to suppress the electron overflow. We introduced Mg-doped InAlGaN for p-type layers of the UV-LEDs for the purpose of obtaining higher hole concentration, and achieved high power CW operations of the UV-LEDs. 340 nm-band InAlGaN-based multi-quantum-well (MQWs) UV-LEDs with Mg-doped InAlGaN electron-blocking layer (EBL) and Mg-doped InAlGaN layers wererngrown on sapphire substrates by metal-organic chemical vapor deposition (MOCVD). The output power of UV-LED with p-InAlGaN layers was approximately 4.7 times larger than that with p-AlGaN layers. Maximum output power and the external quantum efficiency (EQE) of the LED with p-InAlGaN layers were 8.4 mW and 0.9 %, respectively, at emission wavelength of 346 nm under room temperature (RT) CW operation. From these results, p-InAlGaN is shown to be useful for the realization of high-efficiency UV-LEDs.