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在流体静压力(0—2GPa)下,对Hg_(1-x)Cd_xTe n~+-p光电二极管(x=0.5)室温电学特性进行了实验和理论研究。通过考虑深能级压力效应及其对深能级辅助隧道电流的影响,较好地解释了实验上观察到的p-n结伏安特性在小偏压范围下呈现的“反常”压力关系。由对实验数据的理论拟合得到两个深能级:D_l(=E_v+0.75E_g)和D_l(=E_v+0.5E_g),以及相应的电子寿命和空穴寿命,并得到了未掺杂Hg_(1-x)Cd_xTe中深能级的压力系数。 相似文献
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CdZnTe晶体内的空间电荷积累效应是影响高通量脉冲型探测器性能的关键因素.为了探索CdZnTe晶体中深能级缺陷对空间电荷分布及器件性能的影响规律,本文采用Silvaco TCAD软件仿真了CdZnTe晶体内包含位置为Ev+0.86 eV,浓度为1×1012 cm-3的深施主能级缺陷TeCd++时,其空间电荷分布及内电场分布特性.仿真结果表明,随着外加偏压的增加,Au/CdZnTe/Au的能带倾斜加剧,使得晶体内深能级电离度不断增加,空间电荷浓度增加,电场分布死区减小,从而有利于载流子收集.此外,保证CdZnTe晶体高阻的前提下,降低深能级缺陷(Ev+0.86 eV)浓度可使内电场死区减小.深能级缺陷位置为Ev+0.8 eV,亦可以减少阴极附近的空间电荷浓度,使得电场分布更加平坦,死区减小,从而有效地提升载流子的收集效率. 相似文献
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本文报道了对分子束外延(MBE)生长的In0.25Ga0.75As-GaAs应变层量子阱结构在77K下的压力光荧光(PL)研究的结果。流体静压力从0到50kbar.,给出了In0.25Ga0.75As-GaAs应变层量子阱的Γ谷压力系数,实验观察到了量子阱中能级与势垒GaAs中X谷的能级交叉。通过对其压力行为的分析,给出了In0.25Ga0.75As-GaAs异质结的导带与价带跃变比:Qc=△Ec:△Ev=0.68:0.32。对(InGa)As-GaAs应变量子阱常压下的理论分析与实验符合很好。本文也对Al0.3Ga0.70As-GaAs量子阱进行了讨论。
关键词: 相似文献
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利用深能级瞬态谱(DLTS)和光致发光谱(PL),研究了ZnO/pSi异质结的两种不同温度(850℃,1000℃)退火下的深能级中心。发现850℃退火的样品存在3个明显的深中心,分别为E1=Ev+0.21eV,E2=Ev+0.44eV,E3=Ev+071eV;而1000℃退火样品仅存在一个E1=Ev+021eV的中心,且其隙态密度要比850℃退火的大。同时,测量了两个样品的PL谱。发现1000℃退火可消除一些影响发光强度的深能级,对改善晶格结构,提高样品的发光强度有利。 相似文献
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稀有气体原子和水分子组成的范德瓦耳斯复合物是研究水和其他原子分子之间相互作用的典型模型.本文利用中红外连续外腔量子级联激光器结合脉冲超声分子束吸收光谱技术,在D2O弯曲振动带(v2=1←0)附近测量了Ar-D2O复合物4个新的振动转动子带.基于赝双原子分子有效哈密顿量,本文对测量到的振动转动谱线和前人报道的下能级所涉及的纯转动谱线进行了最小二乘法全局拟合,得到了包括振动子能级能量、转动常数和离心畸变常数等在内的精确的基态和激发态分子参数.Ar-D2O的D2O弯曲振动激发的振动带头被精确确定为1177.92144 (32) cm-1,该值比D2O单体的带头红移了约0.458 cm-1.将从实验得到的振动子能级能量与基于四维势能面的理论计算结果进行了比较,检验了理论计算方法的精度. 相似文献
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In the present computational study, we have explored the structural, electronic and optical properties of ZnTe, CdTe and HgTe binary compounds and their ternary alloys ZnxCd1-xTe, ZnxHg1-xTe and CdxHg1-xTe as well as their ordered quaternary ZnxCdyHg1-x-yTe alloys using the full potential linearized augmented plane wave (FP-LAPW) method based on the density functional theory. We have numerically estimated the total energies, the lattice parameters, the bulk moduli and their first pressure derivative using the generalized gradient approximation (GGA). The band structure is computed using the modified Becke-Johnson (TB-mBJ) approximation. Results of our study show a nonlinear dependence of the composition on the lattice constant, bulk modulus and band gap for the binary and ternary compounds as well as for the quaternary alloys. Additionally, the dielectric function, the refractive index and the loss energy were also reported. The pressure effect on the band gap energy and optical properties were also investigated and reported. Our results are in good agreement with experimental values and theoretical data available in the literature. 相似文献
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J. Ren G. Nimtz J. Jakumeit R. Wollrab 《Applied Physics A: Materials Science & Processing》1997,65(3):325-328
0.7 Cd0.3Te photodiodes at temperatures lower than 25 K. The freezeout was seen under the conditions that interband tunneling dominates
the current in the photodiode and that avalanche ionization does not take place. These conditions are fulfilled at temperatures
lower than 25 K and reverse bias voltages around 3 V. An acceptor level of about 4 meV was determined for p-type Hg0.7Cd0.3Te with NA-ND∼1016 cm-3 from the temperature dependence of the photodiode resistance governed by carrier freezeout. The difficulties in observation
of carrier freezeout in Hg1-xCdxTe with a larger composition ratio x or higher doping concentration are discussed.
Received: 21 November 1996/Accepted: 15 April 1997 相似文献
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通过变温I-V测试方法对中波Si基碲镉汞光伏探测器的深能级进行了研究. 首先在产生-复合电流为主导电流机理范围内对Si基碲镉汞探测器的I-1/(kBT)曲线拟合,得到-0.01 V偏压下单元Si基碲镉汞器件的深能级Eg/4.然后对不同偏压下的实验数据进行了拟合、比较,发现不同偏压下起主导作用的深能级与该偏压下的暗电流机理有较好的对应关系. 最后对-0.01 V偏压下不同面积器件的深能级进行了拟合、比较,发现
关键词:
Si基碲镉汞
深能级
产生-复合电流
理想因子 相似文献
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利用X射线粉末衍射方法,在室温高压下观察到了Hg1-xCdxTe(x=0.19)的相变。实验是在DAC高压装置上完成的,压力从0逐步加至10.1 GPa。在常温常压下Hg1-xCdxTe(x=0.19)具有闪锌矿结构。从实验结果看到,在压力为3 GPa和6.8~8.3 GPa之间有两个结构相变存在。初步认为,后一个相变与Hg1-xCdxTe(x=0.19)的金属化有密切关系。通过计算,得到了它在相变前的状态方程,并且与二元HgTe化合物在相变规律上进行了比较。 相似文献
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The electronic and magnetotransport properties of conduction electrons in the grain boundary interface of p-type Hg1−xCdxTe bicrystals are investigated. The results clearly demonstrate the existence of a two-dimensional degenerate n-type inversion layer in the vicinity of the grain boundary. Hydrostatic pressure up to 103 MPa is used to characterize the properties of the two-dimensional electron gas in the inversion layer. At atmospheric pressure three series of quantum oscillations are revealled, indicating that tthree electric subbands are occupied. From quantum oscilations of the magnetoresistivity
the characteristics parameters of the electric subbands (subband populations nsi, subband energies EF−Ei, effective electron masses m*ci) and their pressure dependences are established. A strong decrease of the carrier concentration in the inversion layer and of the corresponding subband population is observed when pressure is applied A simple theoretical model based on the triangular-well approximation and taking into account the pressure dependence of the energy band structure of Hg1−xCdxTe is use to calculate the energy band diagram of the quantum well and the pressure dependence of the subband parameters. 相似文献
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通过变磁场霍耳测量研究了MBE生长的Hg0.80Mg0.20Te薄膜在15 —250K温度范围内的输运特性.采用迁移率谱(MS)和多载流子拟合过程(MCF)相结合的方法对 实验数据进行了分析,由该方法获得的结果和Shubnikov de Hass(SdH)振荡测量的结果都证 明材料中存在二维(2D)电子和三维(3D)电子.其中2D电子主要来自于Hg1-xMgxTe-CdTe的界面积累层或Hg1-x 关键词:
变磁场霍耳测量
界面积累层
二维电子气
1-xMgxTe')" href="#">Hg1-xMgxTe 相似文献