Wang Wenliang, Yang Weijia, Gao Fangliang, Lin Yunhao, Li Guoqiang
State Key Laboratory of Luminescent Materials and Devices, South China University of Technology, Guangzhou 510641, China.
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.
Sci Rep. 2015 Mar 23;5:9315. doi: 10.1038/srep09315.
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.
通过射频分子束外延（RF-MBE）在优化的生长条件下，已在La 0.3 Sr 1.7 AlTaO6（LSAT）衬底上生长出高效的氮化镓基发光二极管（LED）晶圆。已详细表征了在LSAT衬底上制备的氮化镓基LED晶圆的结构特性、表面形貌和光电特性。表征结果表明，GaN(0002)和GaN(10-12)的X射线摇摆曲线的半高宽（FWHM）分别为190.1和210.2角秒，这表明已获得高质量的GaN薄膜。扫描电子显微镜和原子力显微镜测量结果显示，p-GaN表面非常光滑，表面均方根（RMS）粗糙度为1.3 nm。低温和室温光致发光测量有助于计算出内部量子效率为79.0%。通过标准工艺将生长的氮化镓基LED晶圆制成尺寸为300×300μm(2)的LED芯片。在20 mA电流下，LED芯片的正向电压、光输出功率和外部量子效率分别为19.6 W、2.78 V和40.2%。这些结果揭示了LSAT衬底上氮化镓基LED的高光电子特性。这项工作为氮化镓基器件带来了广阔的未来应用前景。
