High-quality gallium nitride （GaN） film was grown on nano-pattemed sapphire substrates （NPSS） and investigated using XRD and SEM. It was found that the optimum thickness of the GaN bulter layer on the NPSS is 15 n...High-quality gallium nitride （GaN） film was grown on nano-pattemed sapphire substrates （NPSS） and investigated using XRD and SEM. It was found that the optimum thickness of the GaN bulter layer on the NPSS is 15 nm, which is thinner than that on micro-patterned sapphire substrates （MPSS）. An interesting phenomenon was observed for GaN film grown on NPSS：GaN mainly grows on the trench regions and little grows on the sidewalls of the patterns at the initial growth stage, which is dramatically different from GaN grown on MPSS. In addition. the electrical and optical properties of LEDs grown on NPSS were characterized.展开更多
We develop a modified two-step method of growing high-density and narrow size-distribution InAs/GaAs quantum dots （QDs） by molecular beam epitaxy. In the first step, high-density small InAs QDs are formed by optimiz...We develop a modified two-step method of growing high-density and narrow size-distribution InAs/GaAs quantum dots （QDs） by molecular beam epitaxy. In the first step, high-density small InAs QDs are formed by optimizing the continuous deposition amount. In the second step, deposition is carried out with a long growth interruption for every 0.1 InAs monolayer. Atomic force microscope images show that the high-density （～5.9 × 10^11 cm^-2） good size-uniformity InAs QDs are achieved. The strong intensity and narrow linewidth （27.7 meV） of the photoluminescence spectrum show that the QDs grown in this two-step method have a good optical quality.展开更多
基金supported by the Suzhou Nanojoin Photonics Co.,Ltd and the High-Tech Achievements Transformation of Jiangsu Province,China(No.BA2012010)
文摘High-quality gallium nitride （GaN） film was grown on nano-pattemed sapphire substrates （NPSS） and investigated using XRD and SEM. It was found that the optimum thickness of the GaN bulter layer on the NPSS is 15 nm, which is thinner than that on micro-patterned sapphire substrates （MPSS）. An interesting phenomenon was observed for GaN film grown on NPSS：GaN mainly grows on the trench regions and little grows on the sidewalls of the patterns at the initial growth stage, which is dramatically different from GaN grown on MPSS. In addition. the electrical and optical properties of LEDs grown on NPSS were characterized.
基金Project supported by the National Natural Science Foundation of China (Grant No 60625405)the Special Foundation forState Major Basic Research Program of China (Grant No 2006CB921504)
文摘We develop a modified two-step method of growing high-density and narrow size-distribution InAs/GaAs quantum dots （QDs） by molecular beam epitaxy. In the first step, high-density small InAs QDs are formed by optimizing the continuous deposition amount. In the second step, deposition is carried out with a long growth interruption for every 0.1 InAs monolayer. Atomic force microscope images show that the high-density （～5.9 × 10^11 cm^-2） good size-uniformity InAs QDs are achieved. The strong intensity and narrow linewidth （27.7 meV） of the photoluminescence spectrum show that the QDs grown in this two-step method have a good optical quality.
