最新刊期
卷 19 ， 期 1 ， 1998
- 摘要：There are a weak surface acoustic coupling but a strong surface optical coupling between the electron and phonon for many polar crystals.In this paper,the properties of the surface polaron of interacting with the deformation potential in polar crystals,which has a weak coupling with surface acoustic phonon and a strong coupling with surface optical phonons,are studied.An effective Hamiltonian of surface polaron of interacting with the deformation potential in polar crystals is derived by using improved linear combination operator and perturbation method.If we consider the interaction between phonons of different wave vectors in the recoil process,the influence on the effective Hamiltonian,the effective mass and the effective interaction potential of the surface polaron of interacting with the deformation potential in polar crystals are discussed.关键词：deformation potential;surface polaron;effective Hamiltonian83|116|0更新时间：2020-08-11
- 摘要：It's beyond common understanding that the luminescent lifetime of 4T1→6A1 transition of Mn2+ doped ZnS decrease drastically by 5 orders of maganitude from bulk to nanacrystal because the magnetic interactions which usuall relax the spin forbiddenness can not be so strong.In this paper,we present a possible mechanism involving in the exchange coulomb interaction between the d electrons of Mn2+ and electrons of host.Assuming that the spin of the ground state of host is not zero,and that the exchange coulomb interaction cause mixing between the excited 4T1 state of Mn2+ and certain excited state of host whose energy is slightly higher than 4T1 state of Mn2+,we found that the spin-forbidden transition could be almost allowed.Morever,the mixing degree increases as the grain size of host decreases.A rough numerical estimation about this mechanism agrees with the results of experiment.关键词：nanocrystal ZnS：Mn2+;luminescence;lifetime;exchange coulomb interaction123|117|0更新时间：2020-08-11
- 摘要：Based on the distribution law P(t)=γe-γt for staying time of single molecule in excited state,this paper simulated the luminescence process of single molecule by Monte Carlo method.The distribution of the time interval between two emission events of a single molecule and the autocorrelation function of the fluorescence intensity were obtained.The simulation features the experimental results reported in the literature recently.关键词：luminescence of single molecule;Monte-Carlo simulation;autocorrelation function110|106|1更新时间：2020-08-11
- 摘要：Nanocrystalline Y2SiO5:Eu was synthesized by Sol-Gel process.The photoluminescence(PL) spectra and quenching concentration of nanocrystalline Y2SiO5:Eu and Y2SiO5:Eu synthesized by high-sintering method were measured and compared.High quenching concentration and stronger luminescence intensity in nanocrystalline Y2SiO5:Eu was observed.This is ascribed to the influence of confinement effect on resonant energy transfer in nanosize particles.These properties show that nanocrystalline Y2SiO5:Eu has potential important applications.关键词：high quenching concentration;Y2SiO5：Eu nanocrystalline;resonant energy transfer113|143|11更新时间：2020-08-11
- 摘要：In the work,we have calculated Judd-Ofelt parameters and the spontaneous emission probabilities of the transitions 3F4→3H4,3H4→3H6,and 3F4→3H5,according to the absorption of Tm3+ in the fluorozirconate glass.The three infrared emission spectra of Tm3+ and the cross relaxation have beem investigated.The effect of the Tm3+ concentration on the infrared emission intensities has been discussed.The emission cross sections of those transitions have been evaluated.关键词：infrared fluorescence;Tm3+ activator;fluorozirconate glass108|122|1更新时间：2020-08-11
- 摘要：Blue electroluminescence was reported for the first time from CaS:TmF3 thin film prepared by radio frequency magnetron sputtering method.Brightness-applied voltage characteristic was investigated in alternating current thin-film electroluminescent device.The integrated intensity ratio of infrared to blue peak of electroluminescent spectra was compared with that of the photoluminescent spectra from CaS:TmF3 powder excited by different photon energy.The main excitation processes in CaS:TmF3 electroluminescent thin film was considered to be energy transfer from the host to Tm3+ centers.108|109|0更新时间：2020-08-11
- 摘要：The crystallinity and morphology of crystalline grains were studied on CaS:TbF3 electroluminescent thin films prepared by electron beam evaporation under different substrate temperatures from 220 to 580℃.The brightness of the electroluminescence strongly increased with increasing the substrate temperatures.X-ray diffraction analysis indicated that the CaS:TbF3 films were polycrystalline with cubic phase.The surface morphology of the films,the decrease of the diffuse reflectance and the increase of transmittance indicated that the CaS:TbF3 films became denser with increasing the substrate temperatures.These changes reduce scattering to hot electrons and finally caused a strong increase of the electroluminescent brightness by increasing hot electrons energy in CaS:TbF3 films.关键词：calcium sulphide;electroluminscence;substrate temperature;surface morphology;crystallinity121|108|0更新时间：2020-08-11
- 摘要：The time-dependence of nonlinear optical absorption in ZnSe-ZnS MQW s has been measured by using pump-probe technique at femtosecond scale at 77K.It appears that the nonlinear response in ZnSe-ZnS MQW s is about 10ps and the turn off time is about 14ps at 77K.The mechanism of nonlinear optical absorption is due to band filling of excitonic states.109|146|0更新时间：2020-08-11
- 摘要：In this paper,a kind of new structure of all solid-state SHG blue laser with an external resonant cavity containing a nonlinear crystal is presented.Laser diode at 860nm is used as a fundamental frequency laser source and nonlinear crystal KTP is used for the frequency doubler.The optical isolator is comprised of a polarizer and a waveplate at λ/4.The half confocal resonator consists of one of end planes of the polarzer and spherical mirror.Stable operation of blue laser of output power of 2mW at 430nm can be obtained,and the distribution of SHG laser intensity is a Gaussian beam.关键词：semiconductor laser;KTP doubler;blue laser136|193|1更新时间：2020-08-11
- 摘要：Photoluminescence of neutron irradiation-induced defects and neutron-transmutation-doping in GaAs was investigated at 10K.The results show that the neutron-transmutation-doping effect can be observed by low temperature photoluminescence.The shift of the CAs related PL peak is attributed to the increase of donors near conduct band after transmutation-doping.Under the conditions of low transmutation doped concentration the transmutated Ge atoms occupy Ga sites;where as after high fluence irradiation and hence high transmutation-doped concentration obtained some part of the transmutated Ge atoms are placed in As sites.For the irradiation of high neutron fluence 1017n/cm2 and after rapid annealing at 800℃ for 20 seconds,there still exist antisite defects GaAs(EV+200meV) and complex defects IGa-VAs,but under the neutron irradiation of fluence 1014n/cm2～1015n/cm2 such defects (mentioned above) have not been found.关键词：GaAs;neutron irradiation;photoluminescence116|137|2更新时间：2020-08-11
- 摘要：nc-Si:H films were prepared using conventional PECVD technique,and its photoluminescence (PL) properties was measured under different temperatures.The results point out that PL peak energy have red shift of 54meV with temperature increase,but light intensity are expotentially reduced after T >80K.The shift of PL peak is due to shrinkage of band gap,and reduction of PL intensity is due to that non-radiation combinations play an important actions in the light emission properties of nc-Si:H films.125|206|2更新时间：2020-08-11
- 摘要：Four complexes of Eu3+ and Tb3+ ions with 2,2'-dipyridyl (Dipy) and 1,10-phenanthroline (Phen) were synthesized in the absolute ethanol solutions,and the fluorescence properties of the complexes were studied.With respect to Dipy,Phen has higher electron density in the conjugated system with the result of a higher orbital overlap and consequently an easier transfer of energy to the rare earth ions,which make the fluorescence intensity of Phen complexes be stronger than that of Dipy complexes.Moreover,the high resolution emission spectra of Eu3+ measured at 77K indicate that the symmetry of Eu3+ sites in Eu(Phen) 2Cl3·2H2O and Eu(Dipy) 2Cl3·2H2O is C1 or C2 or CS.关键词：complexes of rare earths;fluorescence properties;site symmetry156|181|27更新时间：2020-08-11
- 摘要：Effect of melatonin on active oxygen scavange were measured by using several analytic systems.The results showed that melatonin could effectively scavenge active oxygen including O2·,·OH,H2O2 and obviously inhibit DNA damage caused by ·OH.We suggest that melatonin is a efficiency antioxidant.关键词：melatonin;active oxygen;DNA damage;chemiluminescence;antioxidant148|203|4更新时间：2020-08-11
- 摘要：6×21 LED micro-integrated matrix module was developed by light-emitting diode hybrid integration for use of data record and display.In the paper,the designing construction,process and main technical parameter are introduced.120|187|0更新时间：2020-08-11
- 摘要：A waveguide grating with a period of 0 62μm has been built on the glass substrate by special duplicating technique from a master of phase grating.The waveguide grating has been used as coupler of waveguide to experimentally observe that laser beam can be coupled into the waveguide film from above air and the TE mode in waveguide has been excited.关键词：waveguide;grating coupler;holographic grating117|151|1更新时间：2020-08-11
- 摘要：We experimentally demonstrate that AFM can be used as a flexible tool for nondestructive characterisation of all steps of a fabrication sequence of submicrometer gratings for integrated optics without the necessity to specially prepare the samples under test.关键词：integrated optics;submicrometer gratings;atomic-force-microscope107|141|0更新时间：2020-08-11
- 摘要：We have successfuly developed a optic heterodying electronic signals receiving device.Its principle and testing result are reported in this paper.Its technical indices are near to international advanced level.It provide a new method for receiving and dectecting unknow electronic signals in military antagonistic communication.关键词：optic heterodyning;electronic signals;receive103|162|2更新时间：2020-08-11
- 摘要：In this paper,we report the preparation and optical properties of copper doped zinc sulphide aqueous colloid.The effects of size and quantum confinement on the green luminescence properties of ZnS:Cu have been studied.UV absorption shows the energy gap of ZnS:Cu nanocrystallites is 4.186eV.The emission measurements show a large blue shift of the G-Cu luminescence.Luminescence decay times measured in the case of nanoparticles are much faster than that of bulk ZnS:Cu.关键词：nanoparticles;quantum size confinement;luminescence decay time103|253|4更新时间：2020-08-11
- 摘要：The new rare earth complex of Eu(DBM)3bath was synthesized.The experiments show that the Eu(DBM)3bath has both excellent luminescent and better electron transport properties.In the experiments,two-layer electroluminescent devices with the structure of ITO/TPD/Eu(DBM)3bath/Mg/Al were fabricated.The light emission of Eu3+ could be observed at lower voltage of 2.12V and the luminance of 330cd/m2 was obtained at 5V.In addition the devices also shown better stability.关键词：organic electroluminescence;rare earth complex;sharp band emission110|150|6更新时间：2020-08-11
- 摘要：Eu3+ ion doped cadmium aluminium silicate(Abbr.CAS:Eu) glass was prepared.It is found that the CAS:Eu glass shows strong Eu3+ characteristic red emission under 365nm or blue-UV radiation and charge transfer band (CTB) of Eu3+ ions in this galss is not found.The CAS:Eu glass shows the light waveguide phenomenon.关键词：Eu3+ ions;flourescence;glass107|132|4更新时间：2020-08-11
- 摘要：The polymer poly-p-phenylene-vinylene(PPV) was prepared and constructed into single layer thin film electroluminescent devices as ITO/PPV/Al.AC electroluminescence was observed for the first time on our PPV single layer thin film EL devices at frequency 50Hz from 4V to 15V.The emission spectra were recorded by a Hitachi F4010 spectrophotometer and were compared with those driven by DC voltages.The relative emission intensities of two peaks in different AC voltages were measured.It suggested that the mechanism of AC electroluminescence need further study.关键词：polymer;electroluminescence;driven by AC102|152|0更新时间：2020-08-11
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