We report the successful synthesis of Ge clusters embedded in a-SiNy:H matrix prepared by the plasma enhanced chemical vapor deposition(PECVD)method.Chemical and microstructural characteristics of this granular thin f...We report the successful synthesis of Ge clusters embedded in a-SiNy:H matrix prepared by the plasma enhanced chemical vapor deposition(PECVD)method.Chemical and microstructural characteristics of this granular thin film were analyzed using the infrared absorption,x-ray diffraction,Raman scattering,and transmission electron microscopy.Finally we discuss briefly the synthesis mechanism of this new material.展开更多
The a-Ge:H/a-SiNx:H multiquantiim-well structures were prepared by a computercon trolied plasma,enhanced clieinicaJ vapor deposition method and tAeii crystallized by At+laser annealing technique.When the Ge well-layer...The a-Ge:H/a-SiNx:H multiquantiim-well structures were prepared by a computercon trolied plasma,enhanced clieinicaJ vapor deposition method and tAeii crystallized by At+laser annealing technique.When the Ge well-layer thickness was reduced to 30 A,the crystallized sample showed a roojn temperature pLotoluininescence with a peak at about 2.26 eV.Mennwhile some significant characteristics of such a novel Ge na.nostructiire were also revealed by x-ray difEraction.Possible mechanisms of this visible PL phenomenon have been discussed.展开更多
Low-frequency phonon spectra,in a-SiN_(x):H/Si lieterostructures have been observed by means of Brilloiiiii light scattering.Afeasurement of the frequency shift on longi-tudintil and transverse Acoustic phonons as wel...Low-frequency phonon spectra,in a-SiN_(x):H/Si lieterostructures have been observed by means of Brilloiiiii light scattering.Afeasurement of the frequency shift on longi-tudintil and transverse Acoustic phonons as well as on surface phonons enabled us to extract accurately two independent elastic moduli:c_(11) and C_(44) deduced irom phase velocities of bulk acoustic modes and scat taring wavevector^within effective medium approximation.展开更多
Hydrogenated amorphous silicon carbide(a-Sic_(x):H)films were prepared by glow discharge technique with gas mixture of silane(SiH_(4))and methan(CH_(4)).The room-temperature optical bistability was demonstrated in unc...Hydrogenated amorphous silicon carbide(a-Sic_(x):H)films were prepared by glow discharge technique with gas mixture of silane(SiH_(4))and methan(CH_(4)).The room-temperature optical bistability was demonstrated in uncoated a-SiC_(x):H films at the excitation wavelength about 532nm.The switch-on intensity of device is about 0.8 MW/cm^(2) and the switching time is in the nanosecond scale.The physical origin of the optical nonlin5arity in these materials is also discussed.展开更多
The optical properties of amorphous Gap(a-Gap)films prepared by plasma enhanced transport deposition method in the system of Ga-PCl_(3)-H_(2) have been studied.The optical energy band gap E_(g)^(opt) of a-Gap films is...The optical properties of amorphous Gap(a-Gap)films prepared by plasma enhanced transport deposition method in the system of Ga-PCl_(3)-H_(2) have been studied.The optical energy band gap E_(g)^(opt) of a-Gap films is about 1.6 e V which depends on the contents of Cl atoms.The results of exponential absorption edge indicate that there is a high density of band-tail states in the optical energy band gap.展开更多
The hydrogenated amorphous silicon(a-Si:H)/silicon carbide(a-SiCx:H)quantum well(QW)and superlattice structures were fabricated by glow discharge deposition.Wavelength differential absorption spectroscopy has been app...The hydrogenated amorphous silicon(a-Si:H)/silicon carbide(a-SiCx:H)quantum well(QW)and superlattice structures were fabricated by glow discharge deposition.Wavelength differential absorption spectroscopy has been applied to study the subband transition in a-Si:H/a-SiC_(x):H Q W,and derivative spectra change clearly from a linear to a step-like form when a-Si:H well-layer thickness has decreased below 40Å.These results indicate that three-dimensional parabolic band transition is turned into subband transition in the a-Si:H QW.展开更多
基金the National Natural Science Foundation of China.
文摘We report the successful synthesis of Ge clusters embedded in a-SiNy:H matrix prepared by the plasma enhanced chemical vapor deposition(PECVD)method.Chemical and microstructural characteristics of this granular thin film were analyzed using the infrared absorption,x-ray diffraction,Raman scattering,and transmission electron microscopy.Finally we discuss briefly the synthesis mechanism of this new material.
文摘The a-Ge:H/a-SiNx:H multiquantiim-well structures were prepared by a computercon trolied plasma,enhanced clieinicaJ vapor deposition method and tAeii crystallized by At+laser annealing technique.When the Ge well-layer thickness was reduced to 30 A,the crystallized sample showed a roojn temperature pLotoluininescence with a peak at about 2.26 eV.Mennwhile some significant characteristics of such a novel Ge na.nostructiire were also revealed by x-ray difEraction.Possible mechanisms of this visible PL phenomenon have been discussed.
基金Supported by the National Natxu al Science Foiuidation of ChinaScience Found of Chinese Educatioxi Conunittee.
文摘Low-frequency phonon spectra,in a-SiN_(x):H/Si lieterostructures have been observed by means of Brilloiiiii light scattering.Afeasurement of the frequency shift on longi-tudintil and transverse Acoustic phonons as well as on surface phonons enabled us to extract accurately two independent elastic moduli:c_(11) and C_(44) deduced irom phase velocities of bulk acoustic modes and scat taring wavevector^within effective medium approximation.
基金Supported by the National Natural Science Foundation of China.
文摘Hydrogenated amorphous silicon carbide(a-Sic_(x):H)films were prepared by glow discharge technique with gas mixture of silane(SiH_(4))and methan(CH_(4)).The room-temperature optical bistability was demonstrated in uncoated a-SiC_(x):H films at the excitation wavelength about 532nm.The switch-on intensity of device is about 0.8 MW/cm^(2) and the switching time is in the nanosecond scale.The physical origin of the optical nonlin5arity in these materials is also discussed.
文摘The optical properties of amorphous Gap(a-Gap)films prepared by plasma enhanced transport deposition method in the system of Ga-PCl_(3)-H_(2) have been studied.The optical energy band gap E_(g)^(opt) of a-Gap films is about 1.6 e V which depends on the contents of Cl atoms.The results of exponential absorption edge indicate that there is a high density of band-tail states in the optical energy band gap.
基金Supported by the National Natural Science Foundation of China.
文摘The hydrogenated amorphous silicon(a-Si:H)/silicon carbide(a-SiCx:H)quantum well(QW)and superlattice structures were fabricated by glow discharge deposition.Wavelength differential absorption spectroscopy has been applied to study the subband transition in a-Si:H/a-SiC_(x):H Q W,and derivative spectra change clearly from a linear to a step-like form when a-Si:H well-layer thickness has decreased below 40Å.These results indicate that three-dimensional parabolic band transition is turned into subband transition in the a-Si:H QW.
