最新刊期
卷 20 ， 期 1 ， 1999
- 摘要：From the experimental results, it is clear that luminescence intensity of the wafer reaches the maximum, when the thickness of p-type layer (d) in a GaPⅩⅣN light emitting diode is in a range of 12～17μm. Increasing d the effect of the surface recombination might be compressed, making the internal quantum efficiency to be increased. At the same time, it might increase the internal absorption, resulting in a decrease of the extraction efficiency. Combining the two factors, and using the resonable values of the relevant parameters, a rational explanation for the optimum value of dmeasured experimentally is obtained.95|112|0更新时间：2020-08-11
- 摘要：Using chemical etching combined with SEM measurement, the dislocation densities ND of the epilayer and substrate in GaPⅩⅣN LPE wafers from different sources are carried out. The brightness of the samples are measured also. The results indicate that the brightness increases as decreasing of the ND of the epilayer and a dicreasing of the epilayer ND can be caused by decreasing the subctrate ND.关键词：GaPⅩⅣN;dislocation;LED123|86|0更新时间：2020-08-11
- 摘要：The steady-state and transient photoluminescence (PL) of molecular beam epitaxial (MBE) low temperature-grown (LTG) GaAs samples are investigated. A weak but well-distinguished steady-state PL peak is detected from LTG-GaAs.Its peak energy has a blue shift relative to the excitonic PL peak of bulk GaAs. Furthermore, it is confirmed that the decay time of the intrinsic luminescence from bulk GaAs substrate is strongly reduced by the top LTG-GaAs layer, while no essential change occurs for the impurity related (e, A×) luminescence. The transient PL of LTG-GaAs without and after annealing is measured by using up-conversion technique. The information about recombination and trapping centers are obtained.100|116|0更新时间：2020-08-11
- 摘要：The temperature dependence of optical quenching cross section spectra of GaAs1-xPx:EL2 center (x=0～0.08) was studied experimentally. For all samples studied, the peak energy has a red shift as temperature goes up from～40K to ～100K. At the same time, the peak height increases, the larger x is. The spectra can by fitted to a sum of two Gaussian components. The results support that EL2 center has two excited states (e1, e2). It also shows that the extrapolated values at 0K are e1(0)=1.016eV and e2(0)=1.046eV, independing fromx. The temperature and composition dependences of the fitting parameters support the assignment that both e1 and e2 are effective mass states related with L minima of conduction band.101|56|0更新时间：2020-08-11
- 摘要：An investigation on the properties of the temperature dependence and the excitation intensity dependence of photoluminescence of ordered Ga0.52 In0.48 P was carried out. Under the condition of low temperature of T=17K and low excitation intensity, the spectrum profile showed a double peaks structure. Changing the temperature and the excitation intensity respectively, the relative phenomena were discussed and a reasonable explanation was given.104|100|0更新时间：2020-08-11
- 摘要：We have investigated the emission and capture process of native defects in undoped In0.49Ga0.51P grown by MOCVD using DLTS technique and transient photo-resistivity spectroscopy (TPRS) technique. A common defect with an activation energy of about 0.37eV was observed with DLTS technique. It's found that the capture barriers of the defect distributed over 60meV from 180meV to 240meV by TPRS measurements. The distribution can be interpreted as the microscopic fluctuation of atomic arrangements around the defect. The investigation of capture process seems more powerful then emission process in these materials, because of two defects with capture barrier energy 0.06 and 0.40eV, that can not be detected with DLTS technique, were also observed with TPRS measurements.101|71|0更新时间：2020-08-11
- 摘要：The integrated photoluminescence(PL) intensity of disordered Ga0.52In0.48P samples grown by metalorganic vapor phase epitaxy(MOVPE) have been measured as a function of temperature. The fitting to the integrated intensity shows two activation energies in two different temperature regions. Below 100K, the activation energy is about 4meV; above 100K, the activation energy is 35meV. We conclude that the low temperature PL behaviour is likely controlled by carriers thermalization from spatial fluctuations of the band edges followed by non-radiative recombination. The high temperature PL behaviour is suspected to be dominated by a nonradiative path whose characteristic activation energy and transition probability depends upon the degree of sublattice ordering.关键词：photoluminescence;ordering degree;Ⅲ-Ⅴ semiconductors104|83|1更新时间：2020-08-11
- 摘要：Various epitaxial techniques have been utilized for growing GaxIn1-xP epilayers on GaAs substrates (GaInP2/GaAs). Impurities in the epitaxial GaInP2/GaAs seriously effect on its optical and electrical properties. Therefore, it is important to demonstrate what kinds of impurities are common contaminants in epitaxial GaInP2/GaAs. A lot of literatures considered C as a contaminant during growing GaInP2/GaAs epilayers. Our measurements with CAMECA IMS 4F secondary ion mass spectrometer indicated that there exists contaminant Si instead of C in GaInP2/GaAs samples. The shape for the variation of excitation intensity versus peak energy of the photoluminescence (PL) emission nearby 1.17eV in GaInP2/GaAs samples illustrated that 1.17eV PL emission could be considered as a donor-acceptor pair (DAP) transition, and furthermore, as a DAP transition of SiGa-VGa, where SiGa is a silicon donor on a gallium sublattice site and VGa is a gallium vacancy acceptor.关键词：GaInP2/GaAs epilayers;Si-contaminant;a donor-acceptor pair transition90|56|0更新时间：2020-08-11
- 摘要：Undoped GaN epilayers with different surface morphologies were grown by MOVPE, and surfaces of part of epilayers were polished. Luminescence distribution of deep levels, scattering light of defects, and Raman shift were measured by cathodoluminescence, light scattering, and Raman scattering, respectively. The results show that the defects in GaN epilayers influence not only on the luminescence and light scattering properties but also on the Raman shifts.关键词：GaN;defect;optical property93|71|0更新时间：2020-08-11
- 摘要：AlxGa1-xN films with x=0, 0.07, 0.15 grown by LP MOCVD were measured by micro-Raman technique under Z(X,X)Z-configuration. Dependence of Raman shift of A1(LO) mode on Al molar fraction was given by ω(AlxGa1-xN)=(1+0.220x) ω(GaN). Broadening of A1(LO) were demonstrated from spatial correlation effect. E2 modes had little shift except small broadening. It was suggested shift increasing of E2 mode with Al molar fraction increasing and shift decreasing due to strain from underlying GaN co effect it. Under various configurations, A1(TO), A1(LO), E1(TO) and E2 modes were observed, and they followed Raman select rules. Single mode behavior of phonon was supported.关键词：AlxGa1-xN film;micro-Raman diffusion technique;spatial correlation effect single;mode86|97|0更新时间：2020-08-11
- 摘要：At 5.0eV laser excitation, six luminescence emission bands of LPCVD silicon nitride film were observed corresponding to 2.97, 2.77, 2.55, 2.32, 2.10 and 1.90eV respectively. Reports on the gap state model of LPCVD silicon nitride film have been made by this paper. The origin of these emission bands are discussed.关键词：LPCVD;silicon nitride film;luminescence84|183|3更新时间：2020-08-11
- 摘要：Silicon based MIS light emiting tunnel diode shows the possibility for making silicon based light emitting devices that can be used in Very Large Scale Integrated (VLSI) circuits. In this paper, we report the fabrication technique, current voltage (I-V) characteristic and light emission spectra of MIS tunnel diode.关键词：light emission;MIS tunnel diode;surface plasmon112|88|0更新时间：2020-08-11
- 摘要：The fluorescence image of the semiconductor InGaP microdisk is observed and analyzed by a CCD fluorescence microscope system. Under green light excitation, a bright red ring of fluorescence near the edge of microdisk together with some features is observed. As a result, the images reveal the optical disk mode pattern in our InGaP microdisks dominated by Whispering-Gallery modes mixed with other modes.120|61|0更新时间：2020-08-11
- 摘要：The fabrication of 5～15μm diameter GaN microdisks and observation of their fluorescence images are reported. Two different kinds of microscopic fluorescence images depending on the thickness of GaN microdisks were obtained. The optical modes occurred in the GaN microdisks are discussed.关键词：Ⅲ-nitrides semiconductors;optical microcavity;optical microdisk;whispering gallery mode(WGM);surface emitting mode92|67|0更新时间：2020-08-11
- 摘要：The nanometer SiC powders of 8～10nm were synthesized by CVD at 1100℃. A blue luminescence peaked at 2.61eV (～475nm) were observed from the SiC powders at room temperature. The powders were annealed at 600～1000℃ in dry N2 atmosphere by the rapid thermal annealing (RTA). The peak intensity of blue luminescent increases as RTA temperature and decreases when the annealing temperature is higher than 900℃. With XRD, IR, TEM, XPS analysis, we concluded that the blue PL emission is caused by oxygen deficiency defects in the SiC/SiOx interface.关键词：nanometer SiC powders;blue luminescence;rapid thermal annealing(RTA)97|87|1更新时间：2020-08-11
- 摘要：SiOx films with oxygen concentrations in the range 13～46% were deposited by plasma enhanced chemical vapor deposition (PECVD) technique using pure SiH4 and N2O mixture. Erbium was then implanted at an energy of 500keV with dose of 2×1015 ions/cm2. After annealing at temperature in the range 300～950℃, the samples show intense room-temperature luminescence peaked at around 1.54μm. The luminescence intensity increases with increasing oxygen concentration in the film. The Er luminescence depends strongly on the SiOx microstructure. The related mechanism for optical activation and emission was discussed.关键词：erbium-implanted SiOx;photoluminescence89|87|3更新时间：2020-08-11
- 摘要：Si1-yCy alloy with carbon composition of 0.5at.% was successfully grown on Si(100) substrate by solid phase epitaxy recrystallization. The result was presented in this paper. With the help of the SiO2 cap layer, rather uniform carbon profile in amorphous Si layer was obtained by dual-energy implantation. Since ion-flow was small and implantaion time was long enough, respectively, the emergency of β-SiC was avoided and the dynamic annealing effect was depressed. The pre-amorphization of the Si substrate increased the fraction of the substitutional C and the two-step annealing reduced point defects. As a result, Si1-yCy alloy with high quality was recrystallized on Si substrate.关键词：Si1-yCy alloy;ion implantaion;solid phase epitaxy;recrystallization88|63|0更新时间：2020-08-11
- 摘要：In this paper, the temperature dependence of the properties of electron-bulk LO phonon interaction system in a quantum well within the electric-magnetic fields along the growth axis, was studied by means of variational wave-function and harmonic oscillator operator algebra method. The self energy of the system at a finite temperature was obtained. Numerical calculations for GaAs crystal show that the self-energy of the polaron in a quantum well decreases with increasing of well width and electric field and increases with increasing of temperature. The self-energy will increase with increasing of magnetic field for B <51.57T, and it decreases with increasing of magnetic fiald for B >51.57T. When B=51.57T, the self-energy of polaron occurs extreme value, the corresponding resonance frequency ωc=2.5825ω.关键词：quantum well;polaron;self-energy;temperature dependence93|82|1更新时间：2020-08-11
- 摘要：The zeolites matrix nanometer luminescent materials have been prepared conveniently and efficiently by hydrothermal dispersion. Quantum size effect was displayed distinctly on luminescent properties of these materials.关键词：zeolites;nanometer luminescent materials;hydrothermal dispersion method97|71|2更新时间：2020-08-11
- 摘要：One of major factors that have hampered bioluminescent ATP techniques application to biomass assays is the improper removal methods of somatic ATP and inadequate microbial ATP extraction methods that have been used in the ATP rapid microbiology. The experimental study of non-microbial ATP removal methods and the microbial ATP extraction methods has been done. Triton X-100 and apyrase are used as extractant and removal reagent of somatic ATP. Trichlorracetic acid is used to extract microbial ATP. The optimum concentration of them has successively been determined as 0.15%, 0.10% and 1.50%. The comparative research of microbial ATP extraction methods such as ultrasonic disintegration, boiling, ultrasonic boiling, TCA and chloroform has been done. The conclusion is that the trichloroacetic acid is preferable to other extraction methods. The method is simple and easy to be widely used.关键词：rapid microbiology;adenosine triphosphate;bioluminescence109|82|7更新时间：2020-08-11
- 摘要：We fabricated Si tips by one step wet chemical etching <111> silicon substrate in solution of HF:HNO3:H2O=1.5:15:5. The radii of Si-tip's top about 10～15nm is gotten after experiment.关键词：vacuum microelectronics;Si-tip;cold cathode86|83|0更新时间：2020-08-11
- 摘要：The stimulated emission of ZnCdSe/ZnSe single quantum well under an electric field modulation have been studied for the first time. The research result indicates that the peak of stimulated emission has a blue shift first, then red shift, and the intensity of the peak always decreases with the increasing electric field intensity. But under low excitation intensity, the intensity of the stimulated emission decreased with the increasing electric field intensity and it will be quenched at last.86|59|0更新时间：2020-08-11
- 摘要：A novel synthesis method of ZnS:Cu aqueous colloid was studied, in which that the Cu+ was induced to ZnS matrix by sulfurous ligands-thoiurea and thiosulfate. ZnS:Cu colloids were synthesized and the optical properties were studied by absorption spectra, emission spectra and excitation spectra. According to Brus Effective Mass Approximation, the average diameter of ZnS nanoparticles is about 4nm. Excited at about 320nm, a green emission band can be observed, which corresponds to luminescence from copper ions. Cu+ should have entered the lattice of ZnS nanocrystals. Excitation spectra show that the emissions of ZnS:Cu and ZnS colloid have the same luminescent mechanism. In the synthesis route, thiourea and thiosulfate act as ligands and surfactant simultaneously, and their functions can be summarized as Cu+-stabilizing effect, solubility-leveling effect and surface-protecting effect.关键词：ZnS:Cu;nanoparticle;aqueous colloid121|87|1更新时间：2020-08-11
- 摘要：The reactive ion etching (RIE) process at room temperature (RT) was developed to etch GaN grown on sapphire substrates and the p-n junction GaN LEDs were successfully fabricated. BCl3/Cl2 was used as the etching chemistry. The typical etching rate is about 200～300nm/min with selectivity to resist mask above 5:1.关键词：RIE;GaN;blue LEDs88|72|0更新时间：2020-08-11
- Address：No.3888 Dong Nanhu Road, Changchun, Jilin, China Postal code：130033
- Tel：0431-86176862 Email：fgxbt@126.com
- Technical support is provided by Beijing Founder electronics co., LTD 吉ICP备11002662号-17
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0