最新刊期
卷 4 ， 期 2 ， 1983
- 摘要：We have systematically studied the interaction between Mn2+ and Sm3+ centers in ZnS.The emission and excitation spectra and the luminescence decay are measured.It is found that a part of the excitation energy of Mn2+ center can transfer to Sm3+ center.The energy transfer process is nonradia-tive and the interaction between these two centers is dipole-dipole interaction.In the excitation spectrum in which the intensity of Sm3+emission band is recorded for ZnS:Mn,Sm,we have observed five additional bands due to the excitation of Mn2+ion from its ground state 6A1 to different excited states 4T1(4G),4T2(4G),4E(4G),4T2(4D)and 4E(4D).It implies that one can observe the the luminescence of Sm3+ by exciting the Mn2+ center when ZnS is doped with both Mn2+ and Sm3+.As an argument of the energy transfer from Mn2+ to Sm3+,we have shown,in this paper,the emission spectra of ZnS:Mn,Sm under the excitation by laser lines 488nm,514.5nm and 530nm which are close to the excitation bands of Mn2+ center,i.e.490nm and 530nm.95|52|0更新时间：2020-08-11
- 摘要：Auger quenching of radiative transitions of Mn2+ ions and RE3+ ions in ZnS and ZnSe has been investigated by studies of decay curves of electroluminescence of Mn2+ ions and RE3+ ions and thermal quenching of their photoluminescenceDecay curves of electroluminescence of ZnSe:Mn2+ diodes,ZnS:Er3+ thin films and ZnS:Sm3+ thin films were measured under pulsed voltage as shown in Fig.1.Excitation voltage is reverse pulse(Pp+VB).After excitation pulse a constant bias VB is maintained.Decay curves of electroluminescence of Mn2+ ions and RE3+ ions in the samples all consist of a fast components and a slow exponential components.111|65|0更新时间：2020-08-11
- 摘要：The thin films Y2O3-ZnS:Mn-Y2O3 give ACEL with brightness as high as 5000 nit but its efficiency is low(10-3~10-4W/W).The aim of the present work is to find the relation of efficiency of ACEL in ZnS:Mn thin film with the Mn concentration and the origin of concentration quenching.Taking six ZnS:Mn raw materials with Mn concentration varying from 1.5×10-4g/g to 5×10-2g/g,we evaporate them in vacuum ~10-5onto conducting glass to form Y2O3-ZnS:Mn-Y2O3 ACEL thin film.The Mn concentration in these ZnS:Mn thin films varies only by five times(2.7×10-5 to 1.3 ×10-4g/g).In the range of the Mn concentration from 2.7×10-5 to 1.3×10-4g/g,the efficiency of ACEL increases with the Mn concentration.112|55|0更新时间：2020-08-11
- 摘要：In this paper,the behaviour of forming process and the electrical and optical properties in direct current electroluminescent(DCEL)ZnS:Mn,Cu powder panels are presented.By using static and dynamic methods to measure the current-voltage(i~V)characteristic curves of newly-formed panels,it was found that,the curves exhibit a rectifying behaviour and a phase modulation effect(asymmetry in phaseshift),and the luminescent region is localized in adjacent to the anode.In order to further examine whether a barrier is existed in the formed panel,the anode and cathode surface is illuminated by light respectively.Thereis a photovoltaic effect when the anode is illuminated,but not when the cathode is.By inference from this effect,it seems probable that a CuxS-ZnS barrier would be created near the anode of the formed panel.Increasing the forming voltage or prolonging the forming time,the capacitance of the panel decreases and the luminescent region migrates gradually out from the anode into the phosphor layer.At last,the light transmitted from the cathode surface becomes much more intense than that from the anode surface.This fact of migration of luminescent region would be one of the significant factors which cause the panels to age.To analyse the electrical conduction and excitation mechanisms of the panels a p-v-n junction model is proposed.By using the equivalent circuit and simplifying the calculations,the model is able to explain the results obtained by Alder et al.,i.e.,the asymmetry in the i~V characteristics increases with increasing forming voltage;the reciprocal capacitances are linear with the forming voltages for both forward and backward voltage;the lines with different slopes do not pass through the origin of the 1/c~V diagram.Also investigated was the forming process under sinusoidal,20-20kHz source.For gap type devices,several adjacent luminescent regions exist simultaneously even in a gap,and the luminescent regions are nonuniform in shape.Although there are in practice so many factors that may contribute to the forming and aging processes and thus there is at present no common agreement on the processes,we rather consider that the overheating of the phosphor layer is a most important factor inducing the forming and aging processes.121|34|0更新时间：2020-08-11
- 摘要：Zinc sulphide has a high-temperature stable structure at T>1024℃,i.e.wurtzite(2H)and a low-temperature stable structure at T<1024℃,i.e.sphalerite(3C).Much x-ray diffraction study of 2H→3C structure transformations were reported,but the study of 3C→2H structure transformations are little.Especially,the experimental investigations about the orientations of 3C→2H transformations by Laue diffraction haven't been seen as yet.In the present work,the stacking faults were introduced into 3C-ZnS single-crystals by heat treatment,the orientated relation of 3C→MT(micro-twin)→2H transformations was then investigated with Laue back reflection method.Specimens of ZnS single-crystals were prepared with vapour-grown method.It was found by means of x-ray diffraction that the crystallinity of the specimens is fine,and there is no stacking faults in ZnS crystals.The heat treatment condition.1100℃,S vapour protecting the specimens,keeping crystals at high temperature 10 minutes to 5 hours,cooling the specimens in air.The x-ray condition.Cu radiation,35kV,D=37mm,taking Laue back reflection photographs of each specimen in fixed position before and after each heat treatment respectivly.After that,a lot of new Laue diffracted patterns which have not been reported in the literature were observed.In order to interpret these patterns,simple and suitable formulas to index Laue photographs and calculate "anomalous diffracted spots" have been derived,and the stereographic projections corresponding to some crystal planes also have been plotted.All of Laue diffracted spots and streaking in the Laue photographs were indexed and analysed.100|95|0更新时间：2020-08-11
- 摘要：This paper describes a simple and reliable optical method for analysing compositional uniformity of Ga1-xAlxAs epitaxial layer surface using a low power He-Ne laser as a light source.We have measured photoluminescence spectra for n type and p type epitaxial layers with x<0.39 at 300K.Each values of x obtained from the peak of photoluminescence spectra is consistent with that from SEM.From the position of the peak of photoluminescence spectra at different points of the surface,we can quickly and directly show the uniformity of x values.101|37|0更新时间：2020-08-11
- 摘要：The power consumption of ACEL panel is usually measured by a bridge circuit shown in Fig.1.However,it is suitable only in a limited range.In some,it is found in the experiments that:1)the measured value of power consumption car.es depends on the resistance R in the circuit;2)The measured total power consumption when several panels are connected in parallel is smaller than the sum of the power consumption of these panels measured separately.Analysis has shown that this circuit is only suitable for the panels whose resistance is very high and whose capacitance is very low.In addition,the nonlinear nature of the ACEL panels causes larger experimental error.A improved bridge circuit for measuring the power consumption is designed in this paper.Monitoring the change of the phase difference and current,we can easily adjust both the compensation resistor and capacitor to bring the bridge to the equilibrium.Then the resistance of the panel can be determined directly.The new method overcomes the problem mentioned above and has higher sensitivity and precision.Also the nonlinear nature of the panel has little influence for the result of the measurement.99|52|0更新时间：2020-08-11
- 摘要：A new type of electroluminescent matrix display panel is made of ZnS:Mn,Cu powder.This panel can be excited by direct current pulses.The dependence of the emission intensity on the applied pulse voltage,the frequence and the pulse width is discussed.It is pointed out that at low duty the panel can be driven in the mode of frequency or pulse width moduration.The experimental matrix has 50×60 elements with the area of 2mm×2mm.The panel was treated by a forming voltage of 60 volts.107|71|0更新时间：2020-08-11
- 摘要：Two different structures(lateral and end emitting types)infrared LED's have been introduced.The Pp—Ip characteristics at low frequency high pulse current and the emission spectra at direct current have been investigated and analyzed.The results indicate that in the normal case,the LED's have linear Pp—Ip characteristics and Gauss distribution of emission spectrum.For Burrus surface emitting LED's,some of the LED's have abnormal Pp—Ip characteristics,from linear to sublinear to superlinear over the range of 0-3A pulse current,and some LED's have more than one spectrum peak over the range of 20-100mA direct current.96|53|0更新时间：2020-08-11
- 摘要：This paper sums up the current investigation of powdered DCEL phosphors.It is divided into following parts,the effect of raw material,copper-coating technique,spreading and encapsulating technique,phosphor with co-lorsother than orange,forming process,lifetime,application of DCEL and so on.105|59|0更新时间：2020-08-11
- 摘要：So far,it has concluded by all research worker that luminescent region of powdered DCEL panel(sandwich cell)is localized in a thin layer(about one micron)very closed to the anode.It is confirmed by experiments,that there is randomization of luminescent region in powdered DCEL panel.Usually,the position of emission region can not be expected.114|43|0更新时间：2020-08-11
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