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1.
Undoped GaSb is p-type with the residual acceptor concentration of about 1e17 cm−3 due to the gallium vacancies and gallium in antimony site. Counter-doping of GaSb with low level of Te can reduce the net carrier concentration resulting in higher optical transparency in a broad IR spectral range. In this work, the carrier concentration, mobility and sheet resistance of n-type and p-type Te-doped GaSb substrates were measured using Hall method at 300 K and 77 K. The Hall carrier concentration data at 300 K were correlated with the absorption coefficients of GaSb in the IR spectral range. An empirical relationship between these values was established. Based on this correlation, we discuss application of FTIR spectroscopy for non-destructive optical screening of the substrates that allows construction of the carrier concentration distribution map across GaSb wafers. Investigations of the electronic properties of the low-doped p-type and n-type GaSb substrates upon cooling down to 77 K indicate the reduction of the hole carrier concentration background for both GaSb types. This is evident from the decrease in the Hall-measured carrier concentration for p-type GaSb. For n-type GaSb, an increase in the carrier concentration is observed due to the reduction of the hole carrier concentration background. 相似文献
2.
Siyoung Kim Mina Jung Aung Khaing Nyi Joonsuk Song Seunghwan Park 《Applied Surface Science》2009,256(4):1261-1264
We have investigated on the molecular beam epitaxy (MBE) of Te-doped GaSb films on ZnTe buffer. Te-doped GaSb (GaSb:Te) films with and without ZnTe buffer were grown on (0 0 1) GaAs substrates. GaSb:Te/ZnTe/GaAs film revealed higher mobility (=631 cm2/V s) in comparison to GaSb:Te/GaAs film (=249 cm2/V s). To explain the higher mobility of GaSb:Te on ZnTe buffer, dislocation density and temperature dependence of Hall measurement results were analyzed. Temperature dependence of Hall measurement shows strong influence of the dislocation scattering, which indicates that dislocation reduction by the ZnTe buffer enhances the carrier mobility of GaSb films. 相似文献
3.
Yuchun Chang Tao Wang Fei Yin Jingwei Wang Zhenyu Song Yiding Wang Jingzhi Yin 《Infrared Physics & Technology》2011,54(6):478-481
A type-II InAs/GaSb superlattice (SL) was grown on Te-doped (1 0 0) GaSb substrate by low pressure metal organic chemical vapor deposition (LP-MOCVD). The samples were obtained at different growth temperatures and with different interface layers. By introducing an InAsSb interface layer between InAs and GaSb, a good surface morphology of the superlattice was achieved when the sample growth temperature was around 500–520 °C. The photoluminescence (PL) peak wavelength of the sample was 10.7 μm at 77 K, with FWHM of ∼30 meV. 相似文献
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5.
Improvement of the optical and electrical characteristics is essential to get advanced performance from one dimensional (1D) material. Here, we report the first synthesis of a single crystalline Te-doped CdS nanowires (NWs) by a chemical-vapor-deposition (CVD) method. Room temperature photoluminescence (PL) spectra showed that Te concentration plays an important role in tuning emission color from orange to infrared (IR). Decrease in bandgap and PL intensity with increase in Te concentration was observed as compared to undoped CdS NWs. Red and IR emissions were found at 736.5 and 881 nm for doping concentration >6.06%. To our best knowledge, IR emission band has been observed for the first time in CdS NWs. Red-shift of LO phonon mode and its overtone in Raman spectra, and lifetime of red and IR emissions are longer than bandgap of host indicating the doping effect of CdS NWs. Energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD) of the Te-doped CdS NWs further confirms the presence of Te in the CdS NWs. Output characteristics confirm enhanced output current Ids with the increase in doping concentration. A possible growth mechanism was proposed. Doping technique offers to develop high-quality, a very stable, effective, and easily-applicable way to enhance the performance of one dimensional optoelectronic devices and solar cell applications. 相似文献
6.
Undoped p-type Ga Sb single crystals were annealed at 550–600?C for 100 h in ambient antimony. The annealed Ga Sb samples were investigated by Hall effect measurement, glow discharge mass spectroscopy(GDMS), infrared(IR)optical transmission and photoluminescence(PL) spectroscopy. Compared with the as-grown Ga Sb single crystal, the annealed Ga Sb samples have lower hole concentrations and weak native acceptor related PL peaks, indicating the reduction of the concentration of gallium antisite related native acceptor defects. Consequently, the below gap infrared transmission of the Ga Sb samples is enhanced after the thermal treatment. The mechanism about the reduction of the native defect concentration and its influence on the material property were discussed. 相似文献
7.
《Infrared Physics & Technology》1999,40(5):411-415
The relationship of the Te precipitated phase concentration in the matrix to IR transmittance and crystalline quality of as-grown CdZnTe wafers was investigated by means of various optical and structural techniques including infrared (IR) transmission, differential scanning calorimetry (DSC) and Rutherford backscattering spectroscopy (RBS). Results indicate that Te precipitates/inclusions in CdZnTe matrix reduce IR transmittance, especially at concentration ≥0.6 wt.%. Additionally, the crystalline perfection of near-stoichiometric as-grown CdZnTe is better than that of non-stoichiometric samples, and decreases with increasing second-phase concentration. 相似文献
8.
A. Milekhin T. Werninghaus D.R.T. Zahn Y. Yanovskii V. Preobrazhenskii B. Semyagin A. Gutakovskii 《The European Physical Journal B - Condensed Matter and Complex Systems》1998,6(3):295-299
The vibrational spectrum of ultra-thin layer GaSb/AlSb superlattices was investigated in detail by infrared (IR) and Raman
spectroscopies. The effect of confinement of the transverse and longitudinal optical phonons in both types of the layers was
studied. The dispersions of optical phonons of the GaSb and the AlSb obtained from the analysis of the Raman and IR spectra
are in a good accordance with the theoretical data and results of neutron scattering experiments. First- and second-order
Raman spectroscopy indicates the presence of intermixture of atoms at the interfaces in the GaSb/AlSb superlattices.
Received: 11 May 1998 / Accepted: 21 July 1998 相似文献
9.
M.L. Gomez-Herrera P. Rodriguez-Fragoso J.G. Mendoza-Alvarez 《Applied Surface Science》2008,255(3):761-763
In this paper we present results on the characterization of Zn-doped InGaAsSb epitaxial layers to be used in the development of stacked solar cells. Using the liquid phase epitaxy technique we have grown p-type InGaAsSb layers, using Zn as the dopant, and n-type Te-doped GaSb wafers as substrates. A series of Zn-doped InGaAsSb samples were prepared by changing the amount of Zn in the melt in the range: 0.1-0.9 mg to obtain different p-type doping levels, and consequently, different p-n region characteristics. Low temperature photoluminescence spectra (PL) were measured at 15 K using at various excitation powers in the range 80-160 mW. PL spectra show the presence of an exciton-related band emission around 0.642 eV and a band at 0.633 eV which we have related to radiative emission involving Zn-acceptors. Using the photoacoustic technique we measured the interface recombination velocities related to the interface crystalline quality, showing that the layer-substrate interface quality degrades as the Zn concentration in the layers increases. 相似文献
10.
InAs/(GaIn)Sb superlattices for IR optoelectronics: Strain optimization by controlled interface formation 总被引:1,自引:0,他引:1
J. Wagner J. Schmitz N. Herres F. Fuchs D. Serries B. Grietens S. Nmeth C. Van Hoof G. Borghs 《Physica E: Low-dimensional Systems and Nanostructures》1998,2(1-4)
The structural properties of InAs/(GaIn)Sb and (InGa)As/GaSb superlattices (SLs), grown by solid-source molecular-beam epitaxy on
GaAs substrates using a strain relaxed GaSb or InAs buffer layer or directly on
InAs substrates, were analyzed by high-resolution X-ray diffraction and Raman spectroscopy. The residual strain within the SL was found to depend critically on the type of interface bonds, which can be either InSb- or GaAs-like. Thus, to achieve lattice matching to the buffer layer or substrate by strain compensation within the SL stack, the controlled formation of the interface bonds is vital. On the other hand, minimization of the residual strain is shown to be a prerequisite for achieving a high photoluminescence yield and high responsivities for InAs/(GaIn)Sb SL based IR detectors. 相似文献
11.
本文以反射式高能电子衍射(RHEED)和其强度振荡为监测手段,在半绝缘GaAs衬底上成功地生长GaSb/AlSb/GaAs应变层结构,RHEED图样表明,GaSb正常生长时为Sb稳定的C(2×6)结构,AlSb为稳定的(1×3)结构,作者观察并记录GaSb,AlSb生长时的RHEED强度振荡,并利用它成功地生长10个周期的GaSb/AlSb超晶格,透射电子显微镜照片显示界面平整、清晰,采用较厚的AlSb过渡层及适当的生长条件,可在半绝缘GaAs衬底上生长出质量好的GaSb外延层,其X射线双晶衍射半峰宽小于
关键词: 相似文献
12.
C. Ghezzi 《Solid State Communications》2004,130(10):647-652
Magnetoquantum oscillations of the Hall coefficient RH were observed in Te-doped GaSb layers grown by molecular beam epitaxy. The free electron densities were in the low 1016 cm−3 range or even slightly lower, thus achieving, for the first time in GaSb, the extreme quantum limit, where all the electrons occupy the spin-split 0(+) Landau level (LL). Similarly to other known cases, the amplitude of the last maximum of RH could be explained as enhanced by the metal-to-insulator transition of the spin-down electron system in the n=0 LL. The occurrence of the last negative oscillation of RH below its classical value, called Hall dip, could be frustrated, in samples with sufficiently low carrier densities, by an incipient carrier freeze-out at donor impurities induced by the magnetic field. 相似文献
13.
GaInSb/GaSb量子阱结构的低温光致发光谱 总被引:1,自引:0,他引:1
GaInSb三元合金半导体可用于制作工作于1.55~5.5μm波段范围的光电子器件.在光通讯方面,需要2.55μm波长的激光器和接收器,GaInSb半导体合金无疑是一种可选的材料.此外,这种材料也可用于制作高速电子器件,与GaAs基异质结构相比,Ga... 相似文献
14.
基于GaSb薄膜热光伏器件是降低热光伏系统成本的有效途径之一, 本文主要针对GaSb/CdS薄膜热光伏器件结构进行理论分析. 采用AFORS-HET软件进行模拟仿真, 分析GaSb和CdS两种材料各自的缺陷态密度、界面态对电池性能的影响. 根据软件模拟可以得知, 吸收层GaSb的缺陷态密度以及GaSb与CdS之间的界面态密度是影响电池性能的重要因素. 当GaSb缺陷态增加时, 主要影响电池的填充因子, 电池效率明显下降. 而作为窗口层的CdS缺陷态密度对电池性能影响不明显, 当CdS缺陷态密度上升4个数量级时, 电池效率仅下降0.11%. 相似文献
15.
Woong Lee Joonsuk Song Takafumi Yao Hongchan Lee Bonheun Koo 《Applied Surface Science》2008,254(23):7728-7732
We have studied the molecular beam epitaxy (MBE) of GaSb films on GaAs (0 0 1) substrates by using ZnTe as a new buffer layer. GaSb films were grown on two distinct ZnTe surfaces and the influence of surface chemical composition of ZnTe on the morphological and structural properties of GaSb films has been investigated. Initial 2-dimensional (2D) growth of GaSb films is obtained on Zn-terminated surface consequently smooth morphology and high crystal quality GaSb films are achieved. The thin GaSb film (0.4 μm) grown on Zn-terminated ZnTe surface reveals considerably narrow X-ray diffraction linewidth (113 arcsec) along with small residual strain, which strongly supports the availability of ZnTe buffer for the growth of high-quality GaSb film. 相似文献
16.
溶胶-凝胶法制备有机硅掺杂有机/无机复合疏水性减反射膜的研究 总被引:1,自引:0,他引:1
以正硅酸乙酯(TEOS)和硅油为前驱体,在碱性催化体系中制备出有机硅改性二氧化硅溶胶,采用提拉法获得了具备疏水性能的二氧化硅减反膜。通过透射电镜、扫描探针显微镜、红外光谱、分光光度计、表面轮廓仪等多种方法研究了改性后的膜层性能。在高湿度环境中存放两周后,在波长确定的情况下,常规二氧化硅减反膜透过率由99.2%降到了96.5%,疏水改性膜层透过率仍然高于99%。与常规减反膜相比,疏水改性减反膜在高湿度条件下防止潮气侵蚀的性能得到了大幅度的提高。 相似文献
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18.
硫化锌透镜中长波红外宽带增透膜的研制 总被引:4,自引:0,他引:4
硫化锌(ZnS)透镜由于其透光区域较宽,便于光学系统的装校而被经常应用于红外光学系统中,但是其作为基底,镀制中长波红外增透膜却具有相当大的难度,尤其是牢固度的问题。根据任务要求研制的增透膜是在3.5~3.9μm的中波红外波段及9~12μm的长波红外波段,平均透射率大于90%。由于长波红外区可选用的宽透射区材料较少,所以兼顾材料的选用、光谱特性及可靠性满足使用要求等几方面考虑,最终采用氟化钇(YF3)作为低折射率材料,经过多次实验,采用混蒸、离子辅助等工艺方法以及选取合适的基底温度,通过对其他工艺环节的不断改进,解决了在ZnS透镜上镀制宽带增透膜,由YF3膜层严重的应力作用而导致膜层龟裂的问题,最终研制成功符合使用要求,并且可靠性和光谱特性皆优的中长波红外增透膜。 相似文献
19.
Ren-Jie Liu 《中国物理 B》2022,31(7):76103-076103
Integration of the high-quality GaSb layer on an Si substrate is significant to improve the GaSb application in optoelectronic integration. In this work, a suitable ion implantation fluence of 5×1016-cm-2 H ions for GaSb layer transfer is confirmed. Combining the strain change and the defect evolution, the blistering and exfoliation processes of GaSb during annealing is revealed in detail. With the direct wafer bonding, the GaSb layer is successfully transferred onto a (100) Si substrate covered by 500-nm thickness thermal oxide SiO2 layer. After being annealed at 200 ℃, the GaSb layer shows high crystalline quality with only 77 arcsec for the full width at half maximum (FWHM) of the x-ray rocking curve (XRC). 相似文献
20.
J. Teubert P.J. Klar W. Heimbrodt K.Volz W. Stolz A. Polimeni M. Capizzi 《Physica E: Low-dimensional Systems and Nanostructures》2006,32(1-2):218
(Ga,In)(N,As) lattice matched to GaAs with a band gap of 1 eV is employed as active material in high-efficiency III–V solar cells. Te-doped Ga0.934In0.066N0.023As0.977 layers were grown by metal-organic vapor-phase epitaxy on (1 0 0) GaAs. The samples were highly doped n-type with carrier concentrations ranging from about 1017–1019 cm−3. Pieces of the samples were hydrogenated with H-doses of 1018 ion/cm2. The optical and electrical properties of the samples before and after hydrogenation were studied by low-temperature photoluminescence and magnetotransport. In undoped samples hydrogen is known to form N–H complexes which strongly reduce the local perturbation of the lattice due to nitrogen and thus reverse the N-induced global changes of the band structure. Combined analysis of photoluminescence and transport measurements on Te-doped samples, however, indicates a competition between N–H formation and passivation of the Te donor favoring the latter. Hardly any band structure changes due to hydrogenation are observed in these Te-doped samples, instead a strong reduction of the free-carrier concentration is observed after hydrogenation. 相似文献