We report the epitaxial growth of single-crystalline Cd Te（100） thin films on Ga As（100） substrates using molecular beam epitaxy. By controlling the substrate pre-heated temperature with adjustable Te flux, three ...We report the epitaxial growth of single-crystalline Cd Te（100） thin films on Ga As（100） substrates using molecular beam epitaxy. By controlling the substrate pre-heated temperature with adjustable Te flux, three different reconstructed surfaces are realized, and their influence on the subsequent Cd Te growth is investigated. More importantly, we find that both the presence of a thin native oxide layer and the formation of Ga-As-Te bonds at the interface enable the growth along the（100） orientation and help to reduce the threading dislocations and other defects. Our results provide new opportunities for compound semiconductor heterogeneous growth via interfacial engineering.展开更多
We report the growth of InSb layers directly on GaAs （001） substrates without any buffer layers by molecular beam epitaxy （MBE）. Influences of growth temperature and V/Ⅲ flux ratios on the crystal quality, the su...We report the growth of InSb layers directly on GaAs （001） substrates without any buffer layers by molecular beam epitaxy （MBE）. Influences of growth temperature and V/Ⅲ flux ratios on the crystal quality, the surface morphology and the electrical properties of InSb thin films are investigated. The InSb samples with room- temperature mobility of 44600cm2/Vs are grown under optimized growth conditions. The effect of defects in InSb epitaxial on the electrical properties is researched, and we infer that the formation of In vacancy （VIn） and Sb anti-site （SbIn） defects is the main reason for concentrations changing with growth temperature and Sb2/In flux ratios. The mobility of the InSb sample as a function of temperature ranging from 90 K to 360K is demonstrated and the dislocation scattering mechanism and phonon scattering mechanism are discussed.展开更多
The preparation and the microstructure of GaAs embedded with Al nanocrystals prepared by Laser molecular beam epitaxy were investigated.The microstructure of the sample was observed by transmission electron microscope...The preparation and the microstructure of GaAs embedded with Al nanocrystals prepared by Laser molecular beam epitaxy were investigated.The microstructure of the sample was observed by transmission electron microscope.The reflection high-energy electron diffraction(RHEED)pattern varied from the stripe pattern to the spot pattern at the beginning of the Al nanocrystals growth,and then the spot pattern tended to change to the stripe pattern.There was a large lattice mismatch between Al and GaAs substrate,and Al formed three-dimensional islands on the GaAs substrate,which led to the RHEED transformation into the spot pattern.Otherwise,the dislocations would be formed between the GaAs layer and Al islands due to the large lattice mismatch.Meanwhile,there was some polycrystal of GaAs around the Al islands.展开更多
基金Supported by the National Key Research and Development Program of China under Grant Nos 2017YFB0405704 and 2017YFA0305400the 1000-Young Talent Program of Chinathe Shanghai Sailing Program under Grant No 17YF1429200
文摘We report the epitaxial growth of single-crystalline Cd Te（100） thin films on Ga As（100） substrates using molecular beam epitaxy. By controlling the substrate pre-heated temperature with adjustable Te flux, three different reconstructed surfaces are realized, and their influence on the subsequent Cd Te growth is investigated. More importantly, we find that both the presence of a thin native oxide layer and the formation of Ga-As-Te bonds at the interface enable the growth along the（100） orientation and help to reduce the threading dislocations and other defects. Our results provide new opportunities for compound semiconductor heterogeneous growth via interfacial engineering.
基金Supported by the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2015094the National Natural Science Foundation of China under Grant Nos 61204012,61274049 and 61376058+1 种基金the Beijing Natural Science Foundation under Grant Nos 4142053 and 4132070the Beijing Nova Program under Grant Nos 2010B056 and xxhz201503
文摘We report the growth of InSb layers directly on GaAs （001） substrates without any buffer layers by molecular beam epitaxy （MBE）. Influences of growth temperature and V/Ⅲ flux ratios on the crystal quality, the surface morphology and the electrical properties of InSb thin films are investigated. The InSb samples with room- temperature mobility of 44600cm2/Vs are grown under optimized growth conditions. The effect of defects in InSb epitaxial on the electrical properties is researched, and we infer that the formation of In vacancy （VIn） and Sb anti-site （SbIn） defects is the main reason for concentrations changing with growth temperature and Sb2/In flux ratios. The mobility of the InSb sample as a function of temperature ranging from 90 K to 360K is demonstrated and the dislocation scattering mechanism and phonon scattering mechanism are discussed.
文摘The preparation and the microstructure of GaAs embedded with Al nanocrystals prepared by Laser molecular beam epitaxy were investigated.The microstructure of the sample was observed by transmission electron microscope.The reflection high-energy electron diffraction(RHEED)pattern varied from the stripe pattern to the spot pattern at the beginning of the Al nanocrystals growth,and then the spot pattern tended to change to the stripe pattern.There was a large lattice mismatch between Al and GaAs substrate,and Al formed three-dimensional islands on the GaAs substrate,which led to the RHEED transformation into the spot pattern.Otherwise,the dislocations would be formed between the GaAs layer and Al islands due to the large lattice mismatch.Meanwhile,there was some polycrystal of GaAs around the Al islands.
