GaN nanorods have successfully been synthesized on Si(111) substrates via ammoniating ZnO/Ga2O3 films at 950 degrees C. Ga2O3 thin films and ZnO middle layers were deposited in turn on Si(111) substrates by r.f. magne...GaN nanorods have successfully been synthesized on Si(111) substrates via ammoniating ZnO/Ga2O3 films at 950 degrees C. Ga2O3 thin films and ZnO middle layers were deposited in turn on Si(111) substrates by r.f. magnetron sputtering system. ZnO volatilized at 950 degrees C in the ammonia ambience and Ga2O3 reacted to NH3 to fabricate GaN nanorods in the later ammoniating process. The volatilization of ZnO layers played an important role in the fabrication. The structure and composition of the GaN nanorods were studied by X-ray diffraction (XRD) and Fourier transform infrared spectrophotometer (FTIR). The morphology of GaN nanorods was investigated using scanning electron microscopy (SEM) and transmission electronic microscope (TEM). The analyses of measured results revealed that GaN nanorods with hexagonal wurtzite structure were prepared by this method.展开更多
GaN nanorods were synthesized by magnetron sputtering and ammonification system, and the thickness of Tb intermediate layer was changed to study the effect on GaN nanorods. The resultant was tested by scanning electro...GaN nanorods were synthesized by magnetron sputtering and ammonification system, and the thickness of Tb intermediate layer was changed to study the effect on GaN nanorods. The resultant was tested by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM）, and photo- luminescence （PL） spectra. The results show that the thickness of Tb layer has an evident effect on the modality, quality, and luminescence properties of GaN nanorods. PL spectra at room temperature show a very strong emission peak at 368 nm and a weak emission peak at 387 nm, and the intensities of the peak for the produced samples reach the maximum when Tb layer is 20 nm. Finally, the optimal thickness of 20 nm of Tb intermediate layer for synthe- sizing GaN nanostructures is achieved.展开更多
InGaN/GaN epilayers, which are grown on sapphire substrates by the metal-organic chemical-vapour deposition （MOCVD） method, are formed into nanorod arrays using inductively coupled plasma etching via self-assembled ...InGaN/GaN epilayers, which are grown on sapphire substrates by the metal-organic chemical-vapour deposition （MOCVD） method, are formed into nanorod arrays using inductively coupled plasma etching via self-assembled Ni nanomasks. The formation of nanorod arrays eliminates the tilt of the InGaN （0002） crystallographic plane with respect to its GaN bulk layer. Photoluminescence results show an apparent S-shaped dependence on temperature. The light extraction efficiency and intensity of photoluminescence emission at low temperature of less than 30 K for the nanorod arrays are enhanced by the large surface area, which increases the quenching effect because of the high density of surface states for the temperature above 30 K. Additionally, a red-shift for the InGaN/GaN nanorod arrays is observed due to the strain relaxation, which is confirmed by reciprocal space mapping measurements.展开更多
基金This work was financially supported by the Key Research Program of National Natural Science Foundation of China (No. 90301002 and No. 90201025).
文摘GaN nanorods have successfully been synthesized on Si(111) substrates via ammoniating ZnO/Ga2O3 films at 950 degrees C. Ga2O3 thin films and ZnO middle layers were deposited in turn on Si(111) substrates by r.f. magnetron sputtering system. ZnO volatilized at 950 degrees C in the ammonia ambience and Ga2O3 reacted to NH3 to fabricate GaN nanorods in the later ammoniating process. The volatilization of ZnO layers played an important role in the fabrication. The structure and composition of the GaN nanorods were studied by X-ray diffraction (XRD) and Fourier transform infrared spectrophotometer (FTIR). The morphology of GaN nanorods was investigated using scanning electron microscopy (SEM) and transmission electronic microscope (TEM). The analyses of measured results revealed that GaN nanorods with hexagonal wurtzite structure were prepared by this method.
基金financially supported by the National Natural Science Foundation of China (Nos. 90301002 and 90201025)
文摘GaN nanorods were synthesized by magnetron sputtering and ammonification system, and the thickness of Tb intermediate layer was changed to study the effect on GaN nanorods. The resultant was tested by scanning electron microscopy （SEM）, X-ray diffraction （XRD）, transmission electron microscopy （TEM）, high-resolution transmission electron microscopy （HRTEM）, and photo- luminescence （PL） spectra. The results show that the thickness of Tb layer has an evident effect on the modality, quality, and luminescence properties of GaN nanorods. PL spectra at room temperature show a very strong emission peak at 368 nm and a weak emission peak at 387 nm, and the intensities of the peak for the produced samples reach the maximum when Tb layer is 20 nm. Finally, the optimal thickness of 20 nm of Tb intermediate layer for synthe- sizing GaN nanostructures is achieved.
基金Project supported by the SONY-SINANO Joint Project (Grant No. Y1AAQ11001)the Suzhou Solar Cell Research Project,China (Grant No. ZXJ0903)+1 种基金the International S & T Cooperation Projects (SINO-Japan)the Science Fund of the Ministry of Science and Technology of the People’s Republic of China (Grant No. 2010DFA22770)
文摘InGaN/GaN epilayers, which are grown on sapphire substrates by the metal-organic chemical-vapour deposition （MOCVD） method, are formed into nanorod arrays using inductively coupled plasma etching via self-assembled Ni nanomasks. The formation of nanorod arrays eliminates the tilt of the InGaN （0002） crystallographic plane with respect to its GaN bulk layer. Photoluminescence results show an apparent S-shaped dependence on temperature. The light extraction efficiency and intensity of photoluminescence emission at low temperature of less than 30 K for the nanorod arrays are enhanced by the large surface area, which increases the quenching effect because of the high density of surface states for the temperature above 30 K. Additionally, a red-shift for the InGaN/GaN nanorod arrays is observed due to the strain relaxation, which is confirmed by reciprocal space mapping measurements.
