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1.
S. ChoA. Majerfeld J.J. SánchezE. Muñoz J.M.G. TijeroJ.I. Izpura 《Microelectronics Journal》2002,33(7):531-534
We investigated the temperature dependence of the piezoelectric constant e14, i.e. the pyroelectric effect, of various strained InGaAs/GaAs single- and multi-quantum wells embedded in p-i-n structures grown on (111)B GaAs substrates and diodes made from these structures. Both photoreflectance spectroscopy and differential photocurrent spectroscopy were applied to obtain e14 over the temperature range 11-300 K. The values of e14 for InxGa1−xAs quantum well layers with x=0.12-0.21 were observed to increase with temperature, which is contrary to the expected dependence, and the strain-induced components of the pyroelectric coefficients were quantitatively determined. The dependence of the pyroelectric coefficient on In fraction is discussed. 相似文献
2.
In this report,the diffusion of Zn,Zn-Cd in In_xGa_(1-x)As is investigated using ZnAs_2 and ZnAs_2+Cd as diffusion sources. The effect of the diffusion temperature,diffusion time,a variety of the diffusion source and composition x of the material on the relation of the(X_j-t~(1/2))are given.The diffusion velocity X_j~2/t of Zn in In_xGa_(1-x)As is faster than that of Zn-Cd in In_xGa_(1-x)As,and at 500-600℃,the surface acceptor concentration is from 1×10~(19)to 2×10~(20)cm~(-3),which is higher than that of Zn in InP.Reduction of contact resistance by use of In_xGa_(1-x)As contact layer for 1.3μm LED can be expected. 相似文献
3.
V. A. Solov’ev I. V. Sedova A. A. Toropov Ya. V. Terent’ev S. V. Sorokin B. Ya. Mel’tser S. V. Ivanov P. S. Kop’ev 《Semiconductors》2001,35(4):419-423
The fabrication of new hybrid AlAsSb/InAs/Cd(Mg)Se heterostructures by molecular beam epitaxy and investigation of their structural, luminescent, and transport properties are reported for the first time. These structures show intense luminescence both in the infrared and in the visible regions of the spectrum. This factor, taken together with structural data, indicates a heterointerface of high quality between the III–V and II–VI layers. A theoretical estimate is made of the relative positions of energy bands in the proposed hybrid structures, indicating that the InAs/CdSe interface is a type-II heterojunction, whereas the InAs/Cd0.85Mg0.15Se interface is a type-I heterojunction with a large valence band offset ΔE v≈1.6 eV. The data obtained on the longitudinal electron transport at the InAs/Cd(Mg)Se heterointerface are in good agreement with the theoretical estimate. 相似文献
4.
I. V. Sedova S. V. Sorokin A. A. Toropov V. A. Kaigorodov S. V. Ivanov P. S. Kop’ev E. V. Lutsenko V. N. Pavlovskii V. Z. Zubelevich A. L. Gurskii G. P. Yablonskii Y. Dikme H. Kalisch A. Szymakowski R. H. Jansen B. Schineller M. Heuken 《Semiconductors》2004,38(9):1099-1104
Photoluminescence and lasing at a wavelength of λ=510–530 nm (green spectral region) in Cd(Zn)Se/ZnMgSSe structures with a different design of the active region are studied in a wide range of temperatures and nitrogen laser pump intensities. A minimal lasing threshold of 10 kW/cm2, a maximal external quantum efficiency of 12%, and a maximal output power of 20 W were obtained for the structure with the active region composed of three ZnSe quantum wells with fractional-monolayer CdSe inserts. The lasers exhibited a high temperature stability of the lasing threshold (characteristic temperature T 0=330 K up to 100°C). For the first time, an integrated converter composed of a green Cd(Zn)Se/ZnMgSSe laser optically pumped by a blue InGaN/GaN laser that is grown on a Si (111) substrate and incorporates multiple quantum wells is suggested and studied. 相似文献
5.
研究了GaInNAs/GaAs多量子阱在不同温度和激发功率下的光致发光(PL)谱以及光调制反射(PR)谱.发现PL谱主发光峰的能量位置随温度的变化不满足Varshni关系,而是呈现出反常的S型温度依赖关系.进一步测量,特别是在较低的激发光功率密度下,发现有两个不同来源的发光峰,它们分别对应于氮引起的杂质束缚态和带间的激子复合发光.随温度变化,这两个发光峰相对强度发生变化,造成主峰(最强的峰)的位置发生切换,从而导致表观上的S型温度依赖关系.采用一个基于载流子热激发和出空过程的模型来解释氮杂质团簇引起的束缚态发光峰的温度依赖关系. 相似文献
6.
I. L. Krestnikov M. V. Maksimov S. V. Ivanov N. N. Ledentsov S. V. Sorokin A. F. Tsatsul’nikov O. G. Lyublinskaya B. V. Volovik P. S. Kop’ev S. M. Sotomayor Torres 《Semiconductors》1997,31(2):127-131
The optical properties of structures with submonolayer inclusions of CdSe in a Zn(S,Se) matrix are studied. The submonolayer coating consists of a group of nanosized (40 Å) islands with a height of one monolayer. The exciton oscillator strength of multiple submonolayer CdSe-ZnSSe structures is substantially increased compared to the case of a uniform quantum well of comparable thickness and composition. In submonolayer structures lasing takes place immediately next to the energy of the ground state of the heavy exciton, in contrast with ordinary quantum wells of ZnCdSe, where it is strongly shifted to longer wavelengths by the energy of a single optical phonon. This effect results from the removal of the momentum selection rules during radiative recombination of excitons in submonolayer structures. 相似文献
7.
Jaime M. Martin S. García F. Calle I. Mártil G. Gonzalez-Diaz 《Journal of Electronic Materials》1995,24(1):59-67
Mg, Mg/P, and Mg/Ar implantations were performed into InP:Fe with an energy of 80 keV for obtaining shallow p+ layers suitable for device applications. After rapid thermal annealing at 850 or 875°C for 5 or 10 s, activations between
10 and 50% and mobilities as high as 110 cm2/Vs were obtained for the different doses employed. For the implantations with 1014 cm−2, differential Hall measurements showed hole profiles with peak concentrations in the mid-1018 cm-3 range and Hall mobilities of 90 cmWs. However, secondary ion mass spectrometry profiles showed a clear pileup of Mg at the
surface and in-diffusion tails deeper than 2 μ. Phosphorus or Ar co-implantation reduced the Mg in-diffusion and increased
the activation, but not as clearly as in the case of Be implants. Photoluminescence (PL) measurements demonstrated the good
crystalline quality of the material after all the annealing cycles employed. In the photoluminescence spectra, together with
narrow emissions close to the gap wavelength, two broad bands, centered at about 1.3 and 0.87 eV were found, this last being
the dominant emission of the PL spectra from the layers with higher implanted doses. The origin of this band is tentatively
assigned to complexes involving Mg and a defect. 相似文献
8.
Thermally precracked diethylzinc, dimethylcadmium, and diethyltelluride were used for the metalorganic molecular beam epitaxial
growth of (001) ZnTe, CdTe, and CdZnTe films on GaAs substrates. Measurements of the growth rate as a function of the substrate
temperature and the II/VI ratio were used to determine the growth kinetics of (001) ZnTe and CdTe. (001) CdTe,ZnTe, and CdZnTe
films were deposited under near-stoichiometric growth conditions, as determined from the growth kinetics. The best heteroepitaxial
films exhibited x-ray rocking curve full widths at half maximum of 200–210 arc-s. The photoluminescence spectra of the binary
and ternary films at 5K were dominated by features associated with bound and free excitons. Secondary ion mass spectrometry
measurements showed that the films were free of carbon and oxygen. A new mercury precursor, divinylmercury, was used for HgTe
growth. Preliminary results indicated that divinylmercury is a viable mercury source for metalorganic molecular beam epitaxial
growth when it is precracked. 相似文献
9.
用显微光致发光 (μ- PL)平面扫描的方法对 Cd Zn Te(CZT)晶片进行了研究 .分别在 19μm× 16 μm的缺陷区域进行微米尺度和 7.9mm× 6 .0 mm的大面积范围内进行毫米尺度的逐点 PL 测量 .对测得每一点的 PL 谱进行了拟合 ,得到测量点的禁带宽度等参数 ,其平面分布对应于 CZT中 Zn的组分分布 .统计的结果给出禁带宽度的不均匀性 .对样品进行溴抛光后重复类似的测量 ,结果表明禁带宽度的均匀性大为改善 ,接近了材料组分的真实分布 相似文献
10.
M. M. Mezdrogina V. V. Krivolapchuk N. A. Feoktistov É. Yu. Danilovskiĭ R. V. Kuzmin S. V. Razumov S. A. Kukushkin A. V. Osipov 《Semiconductors》2008,42(7):766-771
Luminescence intensity of heterostructures based on n-ZnO/p-GaN:(Er + Zn) and n-ZnO/AlGaN:(Er + Zn) is higher by more than an order of magnitude than the corresponding intensity of separate n-ZnO, p-GaN:(Er + Zn), and AlGaN:(Er + Zn) layers. Most likely, this phenomenon is due to the effective tunneling recombination of charge carriers caused by a decrease in the concentration of the nonradiative recombination centers located between the n-ZnO/p-GaN:(Er + Zn) and n-ZnO/AlGaN:(Er + Zn) layers. 相似文献
11.
12.
H. R. Vydyanath J. A. Ellsworth J. B. Parkinson J. J. Kennedy B. Dean C. J. Johnson G. T. Neugebauer J. Sepich Pok-Kai Liao 《Journal of Electronic Materials》1993,22(8):1073-1080
(Cd,Zn)Te wafers containing Te precipitates have been annealed under well defined thermodynamic conditions at temperatures
below and above the melting of Te. Results of the examination of the wafers with infrared microscopy before and after the
anneals indicate a substantial reduction of the Te precipitates in wafers annealed at temperatures in excess of the melting
point of Te compared with those annealed at temperatures below the melting point of Te. These results confirm the thermomigration
of liquid Te precipitates to be the principally operative mechanism during annealing in the elimination of these precipitates
in (Cd,Zn)Te wafers. The occurrence of Te precipitates in (Hg,Cd)Te epitaxial layers grown on (Cd,Zn)Te substrates containing
Te precipitates is also explained on the basis of thermomigration of these precipitates during LPE growth from the substrates
to the epilayers. Absence of occurrence of Te precipitates in (Hg,Cd)Te epilayers grown on annealed (Cd,Zn)Te substrates with
negligible Te precipitates is also confirmed. Usefulness of annealing (Cd,Zn)Te substrates—to eliminate Te precipitates—prior
to epilayer growth is confirmed via demonstration of improved long wavelength infrared (Hg,Cd)Te device array performance
uniformity in epitaxial layers grown on (Cd,Zn)Te substrates with negligible Te precipitates after annealing. 相似文献
13.
采用溶胶-凝胶法在玻璃基片上制备了纯ZnO薄膜和高浓度Cu掺杂的Co,Cu共掺ZnO(Zn0.90CoxCu0.1-xO,x=0.01,0.03,0.05)薄膜。扫描电镜观察到无论是纯ZnO还是掺杂ZnO薄膜表面都有均匀分布的颗粒,但是在Cu含量较高时均匀性更好。X射线衍射揭示所有样品都具有纤锌矿结构,但是Cu掺杂量的增加使晶格常数略有减小,而晶粒尺寸却略有增大。XPS测试结果表明样品中Co离子的价态为+2价和+3价,Cu离子的价态为+2价和+1价共存。室温光致发光测量在所有样品中均观察到较强的紫外发光峰、蓝光双峰和较弱的绿光发光峰。 相似文献
14.
H. W. Yao J. C. Erickson H. B. Barber R. B. James H. Hermon 《Journal of Electronic Materials》1999,28(6):760-765
Optical properties of Cd0.9Zn0.1Te (CZT) were studied by variable angle spectroscopic ellipsometry (VASE). Measurements made by VASE were performed on CZT
and CdTe samples in air at room temperature at multiple angles of incidence. A parametric function model was employed in the
VASE analysis to determine the dielectric functions ɛ=ɛ1+iɛ2 in the range of 0.75 to 6.24 eV. A two-oscillator analytical model was used to describe the dielectric response of native
oxides on CZT. Surface oxide optical properties and thickness on CZT were also determined in conjunction with the VASE measurement
and analysis of a CdTe sample. Two samples of CZT of different oxide thicknesses were measured and their optical constants
were coupled together in a multiple-sample, multiple-model VASE analysis to resolve correlations between fitting parameters.
Effective medium approximation was used to describe the optical properties of the CZT oxide with roughness. A Kramers-Kronig
self-consistency check of the real and imaginary parts of the Cd0.9Zn0.1Te dielectric functions was performed over the energy range 0.75 to 6.24 eV. A five-Lorentz-oscillator model was employed
to describe the dielectric response of CZT in the range of 1.6 to 6.24 eV. Intensity transmission measurements were made on
the Cd0.9Zn0.1Te and CdTe, showing the absorption energy band edges of ∼1.58 and 1.46 eV, respectively. 相似文献
15.
Yoshikatsu Ichimura Katsumi Kishino Masaru Kuramoto Mitsunari Satake Atsushi Yoshida 《Journal of Electronic Materials》1995,24(3):171-176
Thermal annealing effects on optical and electrical characteristics for p-type and n-type II–VI compound layers (ZnSe, ZnSSe,
and MgZnSSe) and on the emission efficiency of ZnCdSe/Zn(S)Se 6 quantum well (QW) light emitting diodes (LEDs) grown by molecular
beam epitaxy were investigated. It was clarified that serious degradation of optical and electrical characteristics was not
observed up to an annealing temperature of 400°C. In the case of p-MgZnSSe, the maximum permitted annealing temperature was
lower than that of Zn(S)Se. The light output of the ZnCdSe/Zn(S)Se multi QW LEDs was enhanced by a factor of three at optimum
thermal annealing conditions. The study suggests that this thermal effect for LEDs was produced by the improved crystal quality
of ZnCdSe QWs by thermal annealing. 相似文献
16.
Rhodium(III) acetylacetonate was investigated for its physical, thermal and optical properties. Ultraviolet-visible absorption
spectra show absorptions at 320 nm, 260 nm, and 210 nm. Density measurements yielded a value of 1.75 g/cm3. Thermal characteristics were evaluated using differential thermal analysis (DTA). It was found that the compound is not
volatile, decomposing upon heating. If heating rates are rapid enough,e.g. > 2° C/min, melting at 267° C can be observed. If heating rates are slower, decomposition is complete below the melting point.
If the compound is annealed at 267° C for four hours decomposition is complete, yielding 99% pure rhodium metal. In an oxidizing
atmosphere, on the other hand, the compound decomposes into a product containing 75% rhodium metal which appears to be RhO2. 相似文献
17.
S. A. Ringel R. Sudharsanan A. Rohatgi W. B. Carter 《Journal of Electronic Materials》1990,19(3):259-263
Polycrystalline films of Cd1-x
Zn
x
Te (x = 0–0.4) and Cd1-x
Mn
x
Te (x = 0–0.25) were grown by MBE and MOCVD, respectively, on CdS/SnO2/glass substrates to investigate their feasibility for solar cell applications. The compositional uniformity and interface
quality of the films were analyzed by x-ray diffraction, surface photovoltage, and Auger depth profile measurements to establish
a correlation between growth conditions and lattice constant, atomic concentration, and bandgap of the ternary films. MBE-grown
polycrystalline Cd1-x
Zn
x
Te films showed a linear dependence between Zn/(Cd + Zn) beam flux ratio, Zn concentration in the film, and the bandgap. Polycrystalline
Cd1-x
Zn
x
Te films grown at 300° C showed good compositional uniformity in contrast to compositionally non-uniform Cd1-x
Mn
x
Te films grown by MOCVD in the temperature range of 420–450° C. The MBE-grown Cd1-x
Zn
x
Te interface also showed significantly less interdiffusion compared to the MOCVD-grown Cd1-x
Mn
x
Te/CdS interface, where preferential exchange between Cd from the CdS layer and Mn from the Cd1-x
Mn
x
Te film was observed. The compositional uniformity of MOCVD-grown polycrystalline Cd1-x
Mn
x
Te films grown on CdS/SnO2/glass substrates was found to be a strong function of the growth conditions as well as the Mn source. 相似文献
18.
陈力 张家骅 张霞 骆永石 吕少哲 任新光 王笑军 CHEN Li ZHANG Jia-hu ZHANG Xi LUO Yong-shi Lü Shao-zhe REN Xin-guang WANG Xiao-jun 《光电子.激光》2008,19(5):632-635
在还原气氛下利用高温固相反应法制备了Eu3 ,Li 共掺杂的ZnO:Zn 荧光粉.在近紫外光激发基质条件下,该荧光粉材料具有强的来自Eu3 的4f组态内跃迁线状发射及来自基质缺陷相关的绿色可见宽带发射.测量了稳态光谱,漫反射及时间分辨光谱以研究该材料的发光性质及基质向稀土离子的能量传递过程.在还原气氛下因在导带下形成了一系列浅施主能级,暂时储存激发能,施主中心浓度增加使得基质向稀土离子的能量传递效率增强.通过与纯Eu2O3粉末的光谱对比分析,确定了在此材料体系中存在处于两种局域环境的Eu3 .由于在近紫外区的强且有效的吸收,此材料有望成为应用于近紫外激发发光二极管的新型荧光粉. 相似文献
19.
T. Cloitre L. Aigouy M. Di Blasio B. Gil P. Bigenwald N. Briot O. Briot D. Bouchara M. Averous R. L. Aulombard 《Journal of Electronic Materials》1995,24(3):123-129
We present a detailed examination of the optical properties and electronic structure taken from photoreflectance and photoluminescence
data collected on a series of short-period ZnS-ZnSe superlattices grown by low pressure metalorganic vapor phase epitaxy.
We studied the band offset problem and calculated the exciton binding energy using several variational models. The temperature
dependence of the photoluminescence properties of these superlattices was analyzed in the context of a model which includes
the influence of the interfacial disorder. 相似文献
20.
掺氮ZnO薄膜的光电特性及其薄膜晶体管研究 总被引:6,自引:5,他引:1
Using NH3 as nitrogen source gas, N-doped ZnO (ZnO:N) thin films in c-axis orientation were deposited on glass substrates by radio frequency magnetron sputtering at room temperature. The ZnO:N thin films display significant increase of resistivity and decrease of photoluminescence intensity. As-grown ZnO:N material was used as active channel layer and Si3N4 was used as gate insulator to fabricate thin-film transistor. The fabricated devices on glasses demonstrate typical field effect transistor characteristics. 相似文献