Recently, Professor Kang Junyong of Xiamen University and Dr. Chen Kaixuan of Ganzhao Optoelectronics have jointly tackled key problems and have made significant progress in improving the efficiency of green LEDs. The research results were published in IEEE PHOTONICS JOURNAL 14(4) (2022) 8234405 under the title of "High External Quantum Efficiency Green Light Emitting Diodes on Stress-Manipulated AlNO Buffer Layers".
Abstract:
We demonstrated high-brightness InGaN/GaN green light emitting diodes (LEDs) with ex-situ sputtered stress-manipulated AlNO buffer on 4-inch patterned sapphire substrates. The lattice constant of the AlNO buffer was adjusted by oxygen flow. As a result, the dislocation density and the in-plane compressive stress caused by lattice mismatch were greatly reduced, while the interface quality of the InGaN/GaN multiple quantum wells and the uniformity of the indium composition were greatly improved. At 20A/cm2, the external quantum efficiency and wall plug efficiency of the 526.4-nm-green LEDs grown on the sputtered AlNO buffer reached 46.1% and 41.9%, which were both higher than reported values.
