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The sputtering of Hg0.8Cd0.2Te target by low energy Ar+ ions has been simulated using Monte Carlo method. The simulation results show that the concentration of Hg in the surface region of the target after ion bombardment is lower than the one before ion bombardment, but in a deeper region an excess concentration of Hg is produced due to recoil implantation. The excess concentration of Hg there may act as a donor dopant diffusion source for over doping the acceptor levels in the adjacent region and turn the p-type Hg0.8Cd0.2Te into an n-type material.

The impact parameter dependence of electronic energy loss for heavy ions colliding at low velocity with atoms has been studied using the shell-wise local electron-density model. Roothaan-Hartree-Fock wave functions are used to calculate the local electron density of the atoms studied. The Brandt-Kitagawa effective stopping power charge theory is modified to incorporate the effective charge obtained using Fermi-level scattering phase shift calculations based on the density-functional formalism. The theoretical results are compared with available experimental measurements.

We report the first observations of nonlinear feature and optical bistability in n-CdHgTe at 77 K and obtained computer simulated curves, then discuss contribution due to thermal effect.

On the basis of the analytical method of designing aspherical optical waveguide geodesic lenses [J. Opt. Soc. Am. 69, 1248 (1979)], a particular solution for geodesic lenses without any curvature singularity was obtained.

The 19 F(p,αγ) 16 O resonance nuclear reaction at 872.1 keV, with Γ = 4.2 keV was used to measure the depth profiles of fluorine in 19 F + -implanted Pb 1−x Sn x Te and CdTe samples. A deconvolution procedure was performed to extract the depth profiles from the experimental excitation yield curves. The range parameters. Rp, ΔRp and SK, obtained in this experiment were compared with theoretical calculations.

Today radiothermometers have a wide variety of applications in non -contacttememperature measurments and begin in use for estimation of heat flow and ther-mal resistance, in these measurements there are still some problems to be solv- ed, in recent years we have designed a kind of enclosed radiothermometer which can be used for emissivity and temperature measurements simultaneously.Now we have established a mathemeticat model of heat flow through building watts . With this model we can use the enclosed radiothermometer to measure theradiation heat flow and thermal resistance.The advantages of the measurements using enclosed radiothermometer are thatthe emissivity, temperature, heat flow, heat resistance can be measured only byone instrument;the measurement speed is high and the measured surface may not bethermally disturbed. 1. The derivation of radiation heat flow formulas,As shown in Figure 1, from the heat transfer theory for a closed cavity whichconsists of a convex surface (or plan surface) F,enclosd by a concave surface F,the effective radiation power on both surfaces can be expressed respectively asPJ=WJF WF+ (1--e As

The electronic mobility is an important parameter to express HgCdTe characters. The performance of photoconductive detectors, photovoltaic detectors and sprite detectors are all concerned with it. In our work, besides ionized impurity scattering, polar-optical scattering, acoustic deformation potential scattering and piezoelectric scattering, we also consider the dislocation scattering and give the result in accord with experiment. It shows that dislocation scattering is one of the important factors to influence HgCdTe electronic mobility. In our work, we also give a kind of amendment formula of ionized density. In addition, we also discuss the relationships between mobility and temperature and dislocation density. The result shows that, in the region 40K and 100K, the influence of dislocation is important and can not be neglected.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

In recent years ion implantation has been used to develop MCT and other infrared photovoltaic detectors, However, the implanted ions usually have a nonuniform depth profile in the implanted layer, with the typical depth less than lμm, within which the concentration of the implanted species may change over 3 to 4 orders. Thus within the layer there is an electric field outside the space-charge region. The electric field can be estimated with its intensity as high as 1x102-1x103v/am at 77k. In the present work the effect of the electric field is studied to show its way to effect the performance of the infrared photovoltaic detectors. Using the formulae obtained in this work, the RoA, product, responsibility, noise and detectivity of n-on-p Hgo.8Cd0.2Te photovoltaic detector operating at 77k are calculated for 300k backgrond and 27πfield of view. The results show that they are all related to the electric field in the implanted layer. It is interesting that when the electric field direct to the surface of n-region, namely negative field, the RoAlv=0 product contributed by n-region can not be neglected and the responsibility R,. and detectivity De, decrease. In the case of positive electric field, responsibility RA and the noise Vn both increase while the De increases slightly. Our calculation suggests that the proper technology process should be taken in manufacturing the MCT n-on-p infrared photovoltaic detector by use of ion implantation to eliminate the negative field in the n-region in order to avoid the harmful effect. The calculation is performed to show how the electric field in the ion implanted layer on Hg0.8Cd0.2Te to effect the performance of Hg0.8Cd0.2,Te photovoltaic detectors. The result shows that a reverse electric field is unfavorable for the performance of the photovoltaic detectors.

In application, the HgCdTe photovoltaic arrays exist crosstalk. There are many factors to cause it, and the surface channel is one of them. Because there are electric charges on the surface of HgCdTe photovoltaic device, they can form the surface channel between arrays. We calculate the crosstalk caused by diffusion of carrier through the surface channel under applied voltage. Using the LMC crosstalk instrument, we have measured the crosstalk. The calculative values conform to the result of experiment well. It shows that the surface channel is one of the important factors to effect the crosstalk of HgCdTe photovoltaic arrays. The thicker channel of the surface, the greater crosstalk of the arrays. The crosstalk decreases following with increasing of majority concentration.© (1989) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.