title: Highly-efficient GaN-based light-emitting diode wafers on La 0.3 Sr 1.7 AlTaO6 substrates.
abstract: Highly-efficient GaN-based light-emitting diode (LED) wafers have been grown on La 0.3 Sr 1.7 AlTaO6 (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.
authors: State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641, China.
authors: Wenliang
authors: W
authors: Wang
authors: State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641, China.
authors: Weijia
authors: W
authors: Yang
authors: State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641, China.
authors: Fangliang
authors: F
authors: Gao
authors: State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641, China.
authors: Yunhao
authors: Y
authors: Lin
authors: 1] State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641, China [2] Department of Electronic Materials, South China University of Technology, Guangzhou 510641, China.
authors: Guoqiang
authors: G
authors: Li