共查询到18条相似文献,搜索用时 171 毫秒
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用时间分辨光谱研究了很大的Te组分范围内的ZnS1-xTex(x=00 05—085)合金的发光动力学特性,结果表明:不同形态的Te等电子中心具有不同的辐射复 合寿命,从几个ns到几十个ns的范围内变化,当x=015左右时,寿命达到最大值(约 40ns).其物理机理源于不同的Te等电子中心具有不同的局域化特性.当Te组分较小时,等 电子中心从Te1逐渐演变到Te2,Te3或Te4 时,相应发光寿命增加,表现出不断增强 的激子发光局域化特性;而当Te组分较大时,Te原子团变得较大,其局域势与基体原子势的 相互作用增强,等电子中心的局域化特性减弱,而基体价带扩展态特征变得明显起来,相应 发光寿命逐渐减小.还研究了激子束缚能随Te组分的变化以及发光强度随温度的变化关系, 所得结果进一步支持了时间分辨光谱研究所得到的结论.
关键词:
ZnS
等电子中心
时间分辨光谱
局域态 相似文献
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利用20—300K的Hall系数测量和6-300K的红外光吸收,研究了含氧P型CZ硅单晶经450℃不同时间热处理后所产生的热施主问题。Hall系数测量表明:经100hr热处理的样品存在两个施主能级:E1=58meV,E2=110meV。对不同热处理时间的样品,从低温红外光吸收则可看见由于热施主所引起的复杂吸收光谱。这些吸收峰的数目随着热处理时间的加长而增加和加强。利用类氢模型和有效质量理论拟会和计算,可以证明与氧有关的热施主很可能是双重电荷施主。这些双重施主有多种组态,它与450℃热处理的时间有关。
关键词: 相似文献
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P. Migliorato G. Margaritondo P. Perfetti D. Margadonna 《Solid State Communications》1974,14(10):893-896
The increase of nitrogen concentration considerably affects the 1.6°K photoluminescence spectra of very heavily doped GaP:N. The first moment of the spectral emission shifts towards the red, while the ratio of the intensities of large-momentum phonon replicas of A, NN3 and NN1 lines to the no-phonon lines increases. An explanation is proposed in terms of overlapping of the bound exciton wave functions. 相似文献
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M. I. Eremets O. A. Krasnovskij V. V. Struzhkin Ju. A. Timofeev A. M. Shirokov 《高压研究》2013,33(1-6):880-882
Abstract Constructions of a cryogenic diamond anvil system with mechanical clamping press and helium pressure medium for microscopic optical studies are described. Low temperature nonmagnetic cells ø40 and ø20 mm have been developed. GaP samples doped with S, Te and isoelectronic impurities N, NN have been investigated up to 20 GPa at 1.5-300K. 相似文献
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The luminescence decay times of NNi-pair emission are found to decrease when the photoexcitation density is increased from several W/cm2 to 106–107 W/cm2. For lightly N-doped GaP, the reduction is typically from 3000 to 30 nsec (A-line, low temperature); for heavily N-doped GaP it is from about 1000 nsec to a few nanoseconds. From this decay time reduction the onset of a new recombination mechanism is concluded. No mechanism is likely to explain previously reported high gain values for GaP : N. 相似文献
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Sokrates T. Pantelides 《Solid State Communications》1974,14(11):1255-1258
Substitutional oxygen in GaP is known to be a very deep, non-effective-mass-like donor, capable of binding one or two electrons. No conclusive experiment exists for substitutional N in Si. In this paper, the recently developed Pseudo Impurity Theory is applied to these cases. Without employing any adjustable parameters, the two levels of GaP:OP are predicted in good agreement with experiment. Si:N is predicted to behave in a similar way. The implications of these results are discussed. 相似文献
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Lightly tellurium doped epilayers have been grown by the AsCl3GaH2 technique. The position of the residual donors and of the Te donor have been determined by the high resolution photoluminescence technique and the position of the Te donor is found to be coincident with that of the a-donor reported by Cooke et al. within experimental uncertainty. 相似文献
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Venkatachalam Jayalakshmi 《Journal of Physics and Chemistry of Solids》2006,67(4):669-674
The electronic and structural properties of chalcopyrite compounds CuAlX2 (X=S, Se, Te) have been studied using the first principle self-consistent Tight Binding Linear Muffin-Tin Orbital (TBLMTO) method within the local density approximation. The present study deals with the ground state properties, structural phase transition, equations of state and pressure dependence of band gap of CuAlX2 (S, Se, Te) compounds.Electronic structure and hence total energies of these compounds have been computed as a function of reduced volume. The calculated lattice parameters are in good agreement with the available experimental results. At high pressures, structural phase transition from bct structure (chalcopyrite) to cubic structure (rock salt) is observed. The pressure induced structural phase transitions for CuAlS2, CuAlSe2, and CuAlTe2 are observed at 18.01, 14.4 and 8.29 GPa, respectively. Band structures at normal as well as for high-pressure phases have been calculated. The energy band gaps for the above compounds have been calculated as a function of pressure, which indicates the metallic character of these compounds at high-pressure fcc phase. There is a large downshift in band gaps due to hybridatization of the noble-metal d levels with p levels of the other atoms. 相似文献
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Investigations of the general characteristics and distinctive features of sputtering of A
3
B
5 materials (GaP, GaAs, GaSb, InP and InSb) under bombardment with N
2
+
ions have been carried out. From the experimental data, dependences of the sputtering yield of these materials on the incidence
angle and ion energy have been obtained and the surface relief patterns produced by target etching have been studied. It has
been shown that the dependence on energy of the sputtering yield for GaP, GaAs, and InP can be adequately described by the
Haffa-Switkovski formula for binary materials and Yudin’s approximation for elemental targets. Sputtering of GaSb and InSb
proceeds in the surface layer recrystallization mode, and the sputtering yield agrees with calculations based on Onderlinden’s
model. From a comparison of the experimental and calculated dependences, the surface bonding energies have been determined. 相似文献