The crystal quality of p-GaN film depends on the stress-strain during the process of material growth at a certain extent. A smooth high-quality GaN epitaxial layer was grown on sapphire substrate using standard low-te...The crystal quality of p-GaN film depends on the stress-strain during the process of material growth at a certain extent. A smooth high-quality GaN epitaxial layer was grown on sapphire substrate using standard low-temperature(LT) buffer layer by MOCVD. And by testing analysis of correlative experiments,we found that the stress-strain of p-type GaN could be changed by annealing,enhancing the crystal quality.展开更多
We carefully investigated the ferromagnetic coupling in the as-grown and annealed ferromagnetic semiconductor GaMnAs/A1GaMnAs bilayer devices. We observed that the magnetic interaction between the two layers strongly ...We carefully investigated the ferromagnetic coupling in the as-grown and annealed ferromagnetic semiconductor GaMnAs/A1GaMnAs bilayer devices. We observed that the magnetic interaction between the two layers strongly affects the magnetoresistance of the GaMnAs layer with applying the out of plane magnetic field. After low temperature annealing, the magnetic easy axis of the A1GaMnAs layer switches from out of plane into in-plane and the interlayer coupling efficiency is reduced from up to 0.6 to less than 0.4. However, the magnetic coupling penetration depth for the annealed device is twice that of the as-grown bilayer device.展开更多
文摘The crystal quality of p-GaN film depends on the stress-strain during the process of material growth at a certain extent. A smooth high-quality GaN epitaxial layer was grown on sapphire substrate using standard low-temperature(LT) buffer layer by MOCVD. And by testing analysis of correlative experiments,we found that the stress-strain of p-type GaN could be changed by annealing,enhancing the crystal quality.
基金supported by the National Basic Research Program of China (Grant Nos. 2011CB922200 and 2009CB929301)the National Natural Science Foundation of China (Grant Nos. 11174272 and 61225021)+1 种基金 EPSRC-NSFC joint (Grant No. 10911130232/A0402)WANG KaiYou also acknowledges the support of Chinese Academy of Sciences 100 Talent Program
文摘We carefully investigated the ferromagnetic coupling in the as-grown and annealed ferromagnetic semiconductor GaMnAs/A1GaMnAs bilayer devices. We observed that the magnetic interaction between the two layers strongly affects the magnetoresistance of the GaMnAs layer with applying the out of plane magnetic field. After low temperature annealing, the magnetic easy axis of the A1GaMnAs layer switches from out of plane into in-plane and the interlayer coupling efficiency is reduced from up to 0.6 to less than 0.4. However, the magnetic coupling penetration depth for the annealed device is twice that of the as-grown bilayer device.
