We investigate the structural phase transitions and electronic properties of GaAs nanowires under high pressure by using synchrotron x-ray diffraction and infrared reflectance spectroscopy methods up to 26.2 GPa at ro...We investigate the structural phase transitions and electronic properties of GaAs nanowires under high pressure by using synchrotron x-ray diffraction and infrared reflectance spectroscopy methods up to 26.2 GPa at room temperature.The zinc-blende to orthorhombic phase transition was observed at around 20.0 GPa.In the same pressure range, pressureinduced metallization of GaAs nanowires was confirmed by infrared reflectance spectra.The metallization originates from the zinc-blende to orthorhombic phase transition.Decompression results demonstrated that the phase transition from zincblende to orthorhombic and the pressure-induced metallization are reversible.Compared to bulk materials, GaAs nanowires show larger bulk modulus and enhanced transition pressure due to the size effects and high surface energy.展开更多
Undoped and Be-doped InAs（1–x）Sbx（0 ≤ x ≤ 0.71） epitaxial layers were successfully grown on lattice mismatched semi-insulating Ga As（001） substrate with 2° offcut towards 〈110〉. The effect of the In As...Undoped and Be-doped InAs（1–x）Sbx（0 ≤ x ≤ 0.71） epitaxial layers were successfully grown on lattice mismatched semi-insulating Ga As（001） substrate with 2° offcut towards 〈110〉. The effect of the In As buffer layer on the quality of the grown layers was investigated. Moreover, the influence of Sb/In flux ratio on the Sb fraction was examined. Furthermore, we have studied the defects distribution along the depth of the In As Sb epilayers.In addition, the p-type doping of the grown layers was explored. The In As Sb layers were assessed by X-ray diffraction, Nomarski microscopy, high resolution optical microscopy and Hall effect measurement. The In As buffer layer was found to be beneficial for the growth of high quality In As Sb layers. The X-ray analysis revealed a full width at half maximum（FWHM） of 571 arcsec for In As0.87 Sb0.13. It is worth noting here that the Hall concentration（mobility） as low（high） as 5 × 10^（16）cm^（-3）（25000 cm^2 V^（-1）s^（-1）） at room temperature, has been acquired.展开更多
基金Project supported by the National Key R&D Program of China(Grant No.2018YFA0305900)the National Natural Science Foundation of China(Grant No.11604116)+1 种基金Beijing Municipal Natural Science Foundation,China(Grant No.1192017)Youth Innovation Promotion Association,Chinese Academy of Sciences(Grant No.2017156)
文摘We investigate the structural phase transitions and electronic properties of GaAs nanowires under high pressure by using synchrotron x-ray diffraction and infrared reflectance spectroscopy methods up to 26.2 GPa at room temperature.The zinc-blende to orthorhombic phase transition was observed at around 20.0 GPa.In the same pressure range, pressureinduced metallization of GaAs nanowires was confirmed by infrared reflectance spectra.The metallization originates from the zinc-blende to orthorhombic phase transition.Decompression results demonstrated that the phase transition from zincblende to orthorhombic and the pressure-induced metallization are reversible.Compared to bulk materials, GaAs nanowires show larger bulk modulus and enhanced transition pressure due to the size effects and high surface energy.
基金Project supported by the Polish National Science Centre(No.UMO-2015/17/B/ST5/01753)
文摘Undoped and Be-doped InAs（1–x）Sbx（0 ≤ x ≤ 0.71） epitaxial layers were successfully grown on lattice mismatched semi-insulating Ga As（001） substrate with 2° offcut towards 〈110〉. The effect of the In As buffer layer on the quality of the grown layers was investigated. Moreover, the influence of Sb/In flux ratio on the Sb fraction was examined. Furthermore, we have studied the defects distribution along the depth of the In As Sb epilayers.In addition, the p-type doping of the grown layers was explored. The In As Sb layers were assessed by X-ray diffraction, Nomarski microscopy, high resolution optical microscopy and Hall effect measurement. The In As buffer layer was found to be beneficial for the growth of high quality In As Sb layers. The X-ray analysis revealed a full width at half maximum（FWHM） of 571 arcsec for In As0.87 Sb0.13. It is worth noting here that the Hall concentration（mobility） as low（high） as 5 × 10^（16）cm^（-3）（25000 cm^2 V^（-1）s^（-1）） at room temperature, has been acquired.
