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排序方式: 共有273条查询结果,搜索用时 46 毫秒
41.
Cr2 :ZnSe具有很宽的吸收带和发射带,是中红外波段优秀的可调谐激光材料.从吸收光谱、发射光谱以及角度调谐输出对Cr2 :ZnSe晶体的激光输出性能进行了研究.采用真空高温扩散法制备Cr2 :ZnSe晶体,获得了高浓度的Cr2 离子掺杂的厚1.7 mm,直径10 mm的薄片ZnSe晶体.使用中心波长2.05 μm,最大输出功率8 W的Tm离子掺杂的光纤激光器抽运,使用平凹腔结构搭建谐振腔,获得了最大平均功率1.034 W,中心波长2.367 μm,线宽10 nm的连续激光输出.利用角度调谐的方法,对Cr:ZnSe晶体的调谐性能进行了研究,在100 nm范围内获得了调谐输出. 相似文献
42.
H. Stanzl K. Wolf S. Bauer W. Kuhn A. Naumov W. Gebhardt 《Journal of Electronic Materials》1993,22(5):501-503
Metalorganic vapor phase epitaxy (MOVPE) growth experiments of ZnSe on GaAs (100) are described using ditertiary butylselenide
as the selenium source. The growth temperature was varied between 300 and 400°C and the growth rate was determined. Below
a vapor pressure ratio PSe/PZn of about 5, the selenium is the growth limiting component. The quality of the samples was analyzed by Nomarski microscopy,
x-ray diffraction, high resolution transmission electron microscopy, and photoluminescence. Although the selenium-precursor
was not specially purified, a sharp excitonic luminescence appears in samples grown at 400°C. The MOVPE growth of ZnSe still
suffers from prereactions when H2Se is used. The optimum growth is above 450°C even with precursors as DMSe or DESe which are less harmful than the hydride.
This paper reports results obtained with a novel selenium-precursor: ditertiarybutylselenide.1 相似文献
43.
Guanghan Fan J Iwan Davies Nicholas Maung Maxwell J Parrott John O Williams 《Journal of Electronic Materials》1986,15(4):251-255
Epitaxial layers of ZnSe ranging in thickness from 5μm to 30 μm have been grown on GaAs (100) substrates over the temperature
range 240° C to 340° C by atmospheric pressure MOVPE employing dimethylzinc and hydrogen selenide. An optimum growth temperature
of 280 ± 5° C has been identified and when grown at this temperature the ZnSe epitaxial layers exhibit low resistivity (ρ298
K ≤ 10 ohm · cm), a low compensation ratio (θ298
K = 0.27), a carrier mobility (μ298
K) of 250 ±10 cm2V-1s-1) and aren-type (n
298
K = 8.0 × 1014 cm-3). The ratio of photoluminescence intensity measured at 298K and at 12 K is high (104) and is dominated by a sharp emission due to excitons bound to neutral donors at 2.7956 eV. Mass spectrometric investigations
of the chemical reactions occurring inside the reactor in the presence of the GaAs substrate indicate significant surface-controlled
reactivity in the region of 280° C. 相似文献
44.
Splittings and shifts of excitonic states in ZnSe crystals under uniaxial stress along [100], [111] and [110] directions were studied by spatially resolved spectroscopy of both the reflectivity and the photoluminescence (PL) at 5 K. These methods enabled us to check the local strains in different surface microareas of deformed crystals and as a result to reveal the irregular free and bound exciton state shifts related to the influence of the strain nonuniformity and to the presence of structural imperfections (twins) in the crystals. It is shown that elastic deformation of twinned crystals along directions not exactly [111] gives rise to a doublet structure for all the bound exciton lines in the PL spectra. New values of deformation potentials for ZnSe crystals were deduced. The anisotropic influence of the uniaxial stress on the free and bound exciton state splittings was determined. 相似文献
45.
J. Söllner J. Schmoranzer H. Hamadeh B. Bollig E. Kubalek M. Heuken 《Journal of Electronic Materials》1995,24(11):1557-1561
ZnMgSSe heterostructures have been grown in a low-pressure metalorganic vapor phase epitaxy system with the precursors dimethylzinc
triethylamine, ditertiarybutylselenide, tertiarybutylthiol, and biscyclopentadienylmagnesium at 330°C and a total pressure
of 400 hPa. The optimization of the single layers was carried out by means of low temperature photoluminescence. Only the
near band edge emission was observable with negligible deep levels. The heterostructures consisting of a triple ZnSe quantum
well showed intense luminescence which hints at an effective carrier confinement. Scanning transmission electron microscopy
investigations of the heterostructures still showed structural detects since the layers were not lattice matched to the GaAs
substrate yet. 相似文献
46.
M. W. Cho K. W. Koh K. Morikawa K. Arai H. D. Jung Z. Zhu T. Yao Y. Okada 《Journal of Electronic Materials》1997,26(5):423-428
High quality ZnSe(100) substrates have been used for homoepitaxial growth by molecular beam epitaxy. A chemical pretreatment
suitable for ZnSe substrate preparation is determined from x-ray photoemission spectroscopy studies. Thermal cleaning processes
for the ZnSe(100) surface were investigated by insitu reflection high energy electron diffraction and the surface phase diagram for ZnSe(100) was obtained for the first time.
The low temperature photoluminescence spectra recorded from homoepitaxial layers exhibit unsplit free and bound exciton transitions
with strong intensities. The full widths at half maximum of the (400) x-ray diffraction spectra for ZnSe homoepitaxial layer
were 17≈31 arcsec. 相似文献
47.
K. Kimura S. Miwa T. Yasuda L. H. Kuo A. Ohtake C. G. Jin K. Tanaka T. Yao 《Journal of Electronic Materials》1997,26(6):705-709
We have studied the p-type doping in ZnSe molecular beam epitaxial growth using a novel high-power (5 kW) radio frequency
(rf) plasma source. The effect of growth conditions such as the rf power, the Se/Zn flux ratio and the growth temperature
on p-ZnSe:N was investigated. The net acceptor concentration (NA—ND) of around 1 × 1018 cm−3 was reproducibly achieved. The activation ratio ((NA—ND)/[N]) of p-ZnSe:N with NA—ND of 1.2 × 1018 cm−3 was found to be as high as 60%, which is the highest value so far obtained for NA—ND ∼ 1018 cm−3. The 4.2K photoluminescence spectra of p-ZnSe:N grown under the optimized growth condition showed well-resolved deep donor-acceptor
pair emissions even with high NA—ND.
On leave from Sumitomo Electric Industry Ltd.
On leave from Sony Corp. 相似文献
48.
采用化学气相沉积的方法,以Zn粉末为原料,CuSe纳米粒子为催化剂,在Si衬底上成功制备了毫米级ZnSe纳米线。用X射线衍射、EDS和SEM对产物的结构、成分和形貌进行了测试与表征。结果表明:生长的ZnSe纳米线为立方闪锌矿结构,长度达0.35~0.7mm,Zn和Se的摩尔比为1?0.97,其室温光致发光谱显示在325nm波长激发下,ZnSe纳米线在439nm处呈现自由激子的强烈发射,表明生长的ZnSe纳米线具有高的结晶质量。纳米线生长符合氧化还原反应下的气液固生长机制,并证明Cu3Zn合金充当了实际的ZnSe纳米线生长催化剂。 相似文献
49.
本文报导了我们用常压MOCVD法生长的ZnSe单晶膜的光致发光特性。在77K的光致发光光谱中,ZnSe的激子发射峰位于4450,其半高宽为12.6mev。在探索ZnSe反型的过程中,我们在生长过程中掺入氮杂质,获得了氮替代硒的浅受主,其离化能为91mev。 相似文献
50.
Yejin Kim Hyung Soon Im Kidong Park Jundong Kim Jae‐Pyoung Ahn Seung Jo Yoo Jin‐Gyu Kim Jeunghee Park 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(19)
Nanowires (NWs) have witnessed tremendous development over the past two decades owing to their varying potential applications. Semiconductor NWs often contain stacking faults due to the presence of coexisting phases, which frequently hampers their use. Herein, it is investigated how stacking faults affect the optical properties of bent ZnSe and CdSe NWs, which are synthesized using the vapor transport method. Polytypic zinc blende–wurtzite structures are produced for both these NWs by altering the growth conditions. The NWs are bent by the mechanical buckling of poly(dimethylsilioxane), and micro‐photoluminescence (PL) spectra were then collected for individual NWs with various bending strains (0–2%). The PL measurements show peak broadening and red shifts of the near‐band‐edge emission as the bending strain increases, indicating that the bandgap decreases with increasing the bending strain. Remarkably, the bandgap decrease is more significant for the polytypic NWs than for the single phase NWs. This work provides insights into flexible electronic devices of 1D nanostructures by engineering the polytypic structures. 相似文献