Highly-efficient GaN-based light-emitting diode wafers on La0.3Sr1.7AlTaO6 substrates

• Published in: Scientific reports Vol. 5; no. 1; p. 9315
• Main Authors: Wang, Wenliang, Yang, Weijia, Gao, Fangliang, Lin, Yunhao, Li, Guoqiang
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23.03.2015; Nature Publishing Group
• Subjects: 140/133; 147/135; 147/143; 147/3; 639/301/1005/1007; 639/301/1019/1020/1089; Atomic force microscopy; conference-proceeding; Electron microscopy; Growth conditions; Humanities and Social Sciences; Light emitting diodes; Low temperature; Luminescence; Molecular beam epitaxy; multidisciplinary; Photons; Scanning electron microscopy; Science; Substrates; Temperature effects
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/srep09315

Highly-efficient GaN-based light-emitting diode (LED) wafers have been grown on La 0.3 Sr 1.7 AlTaO 6 (LSAT) substrates by radio-frequency molecular beam epitaxy (RF-MBE) with optimized growth conditions. The structural properties, surface morphologies and optoelectronic properties of as-prepared GaN-based LED wafers on LSAT substrates have been characterized in detail. The characterizations have revealed that the full-width at half-maximums (FWHMs) for X-ray rocking curves of GaN(0002) and GaN(10-12) are 190.1 and 210.2 arcsec, respectively, indicating that high crystalline quality GaN films have been obtained. The scanning electron microscopy and atomic force microscopy measurements have shown the very smooth p-GaN surface with the surface root-mean-square (RMS) roughness of 1.3 nm. The measurements of low-temperature and room-temperature photoluminescence help to calculate the internal quantum efficiency of 79.0%. The as-grown GaN-based LED wafers have been made into LED chips with the size of 300 × 300 μm 2 by the standard process. The forward voltage, the light output power and the external quantum efficiency for LED chips are 19.6 W, 2.78 V and 40.2%, respectively, at a current of 20 mA. These results reveal the high optoelectronic properties of GaN-based LEDs on LSAT substrates. This work brings up a broad future application of GaN-based devices.