Whole Metal Oxide-Based Deep Ultraviolet LEDs Using Ga₂O₃-Al₂O₃:Ga₂O₃ Multiple Quantum Wells

In this work, whole metal oxide-based p-NiO/i-Ga₂O₃-i-Al₂O₃:Ga₂O₃ multiple quantum wells (MQWs)/n-HfO₂:Ga₂O₃ deep ultraviolet light-emitting diodes (DUV-LEDs) were manufactured and studied. To investigate the improved luminance of the MQWs, single i-Ga₂O₃ active layer was utilized to replace MQWs in the DUV-LEDs. The vapor cooling condensation system was used to deposit n-HfO₂:Ga₂O₃, i-Ga₂O₃, and i-Al₂O₃:Ga₂O₃ films on sapphire substrate. Besides, the radio frequency magnetron sputtering system was used to deposit p-NiO film onto the MQWs. As the measurement of electroluminescence spectra, the peak emission wavelength of both the devices with MQWs and i-Ga₂O₃ active layer was approximately 243 nm. Compared with the utilization of single i-Ga₂O₃ active layer, the peak luminance intensity of the DUV-LEDs with MQWs was enhanced due to the effective carrier recombination in the i-Ga₂O₃ well caused by the effective carrier block of the i-Al₂O₃:Ga₂O₃ barrier in the MQWs.