共查询到20条相似文献,搜索用时 125 毫秒
1.
2.
分别对带隙较宽(较窄)的p型材料在带隙较窄(较宽)的n型材料之上的碲镉汞(MCT)异质结的能带结构进行了理论分析.在应用的理论模型中提出了一个简单的载流子浓度近似模型用于计入载流子简并效应和导带非抛物线性,同时还考虑到了价带失配的影响.就p-n结位置(zB)和界面电荷密度(Q)两个参数对MCT异质结能带结构的影响进行了系统分析,发现这些影响是不可忽略的.根据这些影响特征,进一步得出了zB和Q参数之间的优化设计规律.
关键词:
碲镉汞(MCT)
异质结
载流子浓度近似 相似文献
3.
在中波响应波段的p型Hg0.709Cd0.291Te(MCT)分子束外延生长薄膜上,利用材料芯片技术获得叠加注入不同硼离子剂量的系列大光敏元面积(500μm×500μm)的n-op-p结.通过测量液氮温度下不同离子注入剂量单元的电流-电压特性和对零偏微分电阻R0分析,观测到p-n结的性能与硼离子注入剂量明显的依赖关系.在另一片薄膜材料(镉组分值为0.2743)上通过该方法获得R0A优于现有常规数值的探测器单元.
关键词:
p-n结
离子注入
碲镉汞薄膜 相似文献
4.
5.
6.
利用变温吸收谱(11—300K)对非故意掺杂液相外延Hg1-xCdxTe进行研究,对吸收边在低温区间(<70K)出现的约7—20meV反常移动现象进行了分析.结果表明该现象是由材料中Hg空位作为受主能级存在而形成的,红移幅度与样品组分/载流子浓度有关.据此估算Hg空位大致位于价带上方约20meV,与Hg空位形成浅受主能级的经验公式计算结果基本符合.该结果可以解释由传统吸收谱方法确定材料禁带宽度略高于材料实际光电响应截止能量值的现象.
关键词:
碲镉汞
液相外延
汞空位
反常吸收 相似文献
7.
对所研制的短波光伏碲镉汞器件进行了变温电流-电压特性和低频噪声研究,测试温度范围255—293K.实验结果表明随着温度的下降,器件的优值因子R0A从45×103Ωcm2增加到7×104Ωcm2.器件在低频区的主要噪 声成分是1/f噪声和产生-复合噪声,在高频区主要是散粒噪声.在测试的偏压内,器件的1/f噪声功率谱密度与流过器件的电流的平方成正比,器件的Hooge系数为3×10-4—7×10-4.从噪声 功率谱密度曲线分析中得到产生-复合噪声的特征时间常数τ,通过τ的温度特性得到了器件的深能级.
关键词:
碲镉汞
优值因子
低频噪声
深能级 相似文献
8.
脉冲激光与碲镉汞相互作用时的冲量耦合 总被引:3,自引:0,他引:3
在激光功率密度为4.0×108~5.0×109Wcm-2的范围内,用冲击摆测量了NdYAG脉冲激光(波长为1.06μm,脉宽为10ns)辐照大气中不同面积的HgCdTe样品时的冲量耦合系数。从理论上建立了等离子体爆轰模型,对激光结束后等离子体的膨胀过程进行了比较详细的描述,用此模型计算了不同能量的脉冲激光与不同面积的HgCdTe相互作用时的冲量耦合系数,计算值与测量值符合得较好。 相似文献
9.
10.
11.
采用射频磁控溅射制备了非晶态结构的Hg1-xCdxTe薄膜,并利用台阶仪、XRD、原子力显微镜、EDS等分析手段对薄膜生长速率、物相、表面形貌、组分比例进行了研究。实验结果表明,溅射气压对薄膜生长速率、微观结构、表面形貌和化学组分有直接影响。随着溅射气压增大,其生长速率逐渐降低。当溅射气压高于1.1 Pa时,薄膜XRD图谱上没有出现任何特征衍射峰,只是在2θ=23°附近出现衍射波包,具有明显的非晶态特征;当溅射气压小于1.1 Pa时,XRD谱表现为多晶结构。另外,随着溅射气压的增加,薄膜表面粗糙度逐渐减小,而且溅射气压对薄膜组成的化学计量比有明显影响,当溅射气压为1.1 Pa时,薄膜中Hg的组分比最低,而Cd组分比最高。 相似文献
12.
Arie Van Riessen Glenn H. Winton Hideyuki Ohyi Michiyo Yoshida 《Micron (Oxford, England : 1993)》1994,25(6):511-517
Various methods have been used to obtain accurate cross-sectional profiles of Hg1-xCdxTe devices after etching. Preliminary measurements from different etching techniques are also presented. Techniques used were scanning electron microscopy with stereo pairs and cleaved cross-sections, topography SEM (multiple detector SEM) and atomic force microscopy. 相似文献
13.
Variable-temperature transmission/absorption spectra are measured on As-doped Hg1-xCdxTe grown by molecular beam epitaxy. The nonlinear temperature-dependent shift of the absorption edge is also observed, which is similar to our previous report on V_textrmHg (unintentionally)-doped HgCdTe. By referring to the empirical formulas of Eg(x, T), the x value of the epilayer is calculated and its inconsistency between the extreme temperatures (e.g. 10 and 300 K) is discussed. The results confirm the assumption of the effect of shallow levels on the shift of the absorption edge, and suggest that the x value (or Eg) in intrinsic/extrinsic-doped HgCdTe should be determined by referring to as low a temperature as possible (e.g. 10 K), and not the commonly used temperatures of 77 or 300 K, when the transmission spectrum should be employed. This can give brief guidelines for fabricating HgCdTe-related devices. 相似文献
14.
S.G. Li Q. Gong C.F. Cao X.Z. Wang R.C. Wang J.P. Fan C.X. Zhang L.Z. Xia 《Infrared Physics & Technology》2011,54(5):445-448
We report on the temperature dependent lasing characteristics of InAs/GaAs quantum dot lasers under continuous wave mode. The five-stacked InAs quantum dots were grown by gas-source molecular beam epitaxy with slightly different thickness. Ridge waveguide laser with stripe width of 6 μm was processed on the growth structure. The characteristic temperature was measured as high as infinity in the temperature range of 80–180 k. With the increase of injection current, the lasing spectra of laser diode broaden gradually at low temperature of 80 k. However, when the operation temperature increases from 80 to 300 K, the width of lasing spectrum reduces gradually from 40 to 2.0 nm. The lasing process is obviously different from that of a reference quantum well laser which widens its width of lasing spectra by increasing operation temperature. These experiments demonstrate that a carrier transfer from the smaller size of dots into larger dots caused by thermal effect play an important role in the lasing characteristic of quantum dot lasers. In addition, the laser can operate at maximum temperature of 80 °C under continuous wave mode with a maximum output power of 52 mW from one facet at 20 °C. A wavelength thermal coefficient of 0.196 nm/K is obtained, which is 2.8 times lower than that of QW laser. The low wavelength thermal coefficient of quantum dot laser is mainly attributed to its broad gain profile and state filling effects. 相似文献
15.
We have reported a one step growth of a high quality β-FeSi2 epitaxial film on hydrogen terminated Si(1 1 1) by using molecular beam epitaxy (MBE) without template layer or post-growth annealing. In the present work, the growth process was studied by analyzing X-ray diffraction (XRD) spectra, reflective high energy electron diffraction (RHEED) and atomic force microscopy (AFM) observations on the samples grown with different growth times from 10 s to 1 h. A phase transformation from γ-FeSi2 to β-FeSi2 was confirmed existing in the crystal film growth, as well as the growth mode changing from three-dimensional (3D) to two-dimensional (2D) mode. 相似文献
16.
V. G. Kesler L. M. Logvinskii V. I. Mashanov O. P. Pchelyakov V. V. Ul’yanov 《Physics of the Solid State》2002,44(4):709-713
This paper reports on a study of the depth profile of components in GeSi heterostructures grown on low-temperature silicon (LTSi: T gr ~ 350–400° C) and porous silicon by molecular-beam epitaxy. An excess Ge concentration was found by Auger electron spectroscopy depth profiling at the GexSi1?x /LTSi interface, which decreased in all samples subjected to annealing. The Ge diffusion activation energy was calculated to be E a ≈ 1.6 eV in this case. An enhanced Ge concentration was also detected by x-ray photoelectron spectroscopy at the Si cap surface. Possible reasons for the surface enrichment of the silicon layer and of the GexSi1?x film interface by germanium are considered, and the relation between the component distribution and the structural features of plastically strain-relieved layers are discussed. 相似文献
17.
18.
LaTiO3 是一种典型的强关联电子材料, 其(110) 薄膜为通过晶格对称性、应变等的设计调控外延结构的物理性质提供了新的机会. 本文研究了SrTiO3(110) 衬底表面金属La 和Ti 沉积所引起的微观结构变化, 进而利用电子衍射信号对分子束外延薄膜生长表面阳离子浓度的灵敏响应, 发展了原位、实时、精确控制金属蒸发源沉积速率的方法, 实现了高质量LaTiO3(110) 薄膜的生长和对阳离子化学配比的精确控制. 由于LaTiO3中Ti3+ 3d 电子的库仑排斥作用, 氧原子层截止的(110) 表面更容易实现极性补偿, 因此生长得到的薄膜表面暴露出单一类型的氧截止面. 相似文献
19.
G. B. Galiev V. G. Mokerov V. V. Saraikin Yu. V. Slepnev G. I. Shagimuratov R. M. Imamov É. M. Pashaev 《Technical Physics》2001,46(4):411-416
Silicon distribution before and after thermal annealing in thin doped GaAs layers grown by molecular beam epitaxy on (100)-, (111)A-, (111)B-oriented substrates is studied by X-ray diffraction and SIMS. The surface morphology of the epitaxial films inside and outside an ion etch crater that arises during SIMS measurements is studied by atomic force microscopy. Distinctions in the surface relief inside the crater for different orientations have been revealed. Observed differences in the doping profiles are explained by features of the surface relief developing in the course of ion etching in SIMS measurements and by enhanced Si diffusion via growth defects. 相似文献
20.
Wenting Xu Hailing TuQinghua Xiao Qing ChangZongfeng Li Dali Liu 《Applied Surface Science》2011,257(22):9260-9263
The Si1−xGex thin layer is fabricated by two-step Ge ion implantation into (0 0 1) silicon. The embedded SiGe nanoclusters are produced in the Si1−xGex layer upon further annealing. The number and size of the nanoclusters changed due to the Ge diffusion during annealing. Micro defects around the nanoclusters are illustrated. It is revealed that the change of Si-Si phonon mode is causing by the nanoclusters and micro defects. 相似文献