Nonpolar （1150） a-plane GaN films are grown by metal-organic chemical vapour deposition （MOCVD） on r-plane （1102） sapphire. The samples are irradiated with neutrons under a dose of 1× 1015 cm-2. The surface...Nonpolar （1150） a-plane GaN films are grown by metal-organic chemical vapour deposition （MOCVD） on r-plane （1102） sapphire. The samples are irradiated with neutrons under a dose of 1× 1015 cm-2. The surface morphology, the crystal defects and the optical properties of the samples before and after irradiation are analysed using atomic force microscopy （AFM）, high resolution X-ray diffraction （HRXRD） and photoluminescence （PL）. The AFM result shows deteriorated sample surface after the irradiation. Careful fitting of the XRD rocking curve is carried out to obtain the Lorentzian weight fraction. Broadening due to Lorentzian type is more obvious in the as-grown sample compared with that of the irradiated sample, indicating that more point defects appear in the irradiated sample. The variations of line width and intensity of the PL band edge emission peak are consistent with the XRD results. The activation energy decreases from 82.5 meV to 29.9 meV after irradiation by neutron.展开更多
Si-doped (11-20) a-plane GaN grown on (1-102) r-plane sapphire substrate was obtained by metal organic chemical vapor deposition.The optical and electrical properties of the Si-doped a-plane GaN films were investigate...Si-doped (11-20) a-plane GaN grown on (1-102) r-plane sapphire substrate was obtained by metal organic chemical vapor deposition.The optical and electrical properties of the Si-doped a-plane GaN films were investigated by photoluminescence spectroscopy,high-resolution X-ray diffraction,atomic force microscopy and Hall measurement.The results showed that the morphology and the crystal quality slightly degraded with Si doping.The yellow luminescence was enhanced with increasing the flow rate of the SiH4.The significant improvement of the mobility should associate with some of the vacancy filled with the Si.展开更多
基金supported by the National Key Science and Technology Special Project,China (Grant No.2008ZX01002-002)the Major Program and State Key Program of the National Natural Science Foundation of China (Grant Nos.60890191 and 60736033)the Fundamental Research Funds for the Central Universities,China (Grant No.JY10000904009)
文摘Nonpolar （1150） a-plane GaN films are grown by metal-organic chemical vapour deposition （MOCVD） on r-plane （1102） sapphire. The samples are irradiated with neutrons under a dose of 1× 1015 cm-2. The surface morphology, the crystal defects and the optical properties of the samples before and after irradiation are analysed using atomic force microscopy （AFM）, high resolution X-ray diffraction （HRXRD） and photoluminescence （PL）. The AFM result shows deteriorated sample surface after the irradiation. Careful fitting of the XRD rocking curve is carried out to obtain the Lorentzian weight fraction. Broadening due to Lorentzian type is more obvious in the as-grown sample compared with that of the irradiated sample, indicating that more point defects appear in the irradiated sample. The variations of line width and intensity of the PL band edge emission peak are consistent with the XRD results. The activation energy decreases from 82.5 meV to 29.9 meV after irradiation by neutron.
基金supported by the National Key Science & Technology Special Project (Grant No. 2008ZX01002-002)the National Natural Science Founda-tion of China (Grant Nos. 60890191, 60736033)the Fundamental Research Funds for the Central Universities (Grant No. JY10000904009)
文摘Si-doped (11-20) a-plane GaN grown on (1-102) r-plane sapphire substrate was obtained by metal organic chemical vapor deposition.The optical and electrical properties of the Si-doped a-plane GaN films were investigated by photoluminescence spectroscopy,high-resolution X-ray diffraction,atomic force microscopy and Hall measurement.The results showed that the morphology and the crystal quality slightly degraded with Si doping.The yellow luminescence was enhanced with increasing the flow rate of the SiH4.The significant improvement of the mobility should associate with some of the vacancy filled with the Si.
