共查询到19条相似文献,搜索用时 906 毫秒
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报道了利用ZnO和Li2O混合物在5GPa, 1200 ℃—1500 ℃条件下, 制备Li掺杂p型ZnO(记作ZnO: Li)固溶体的过程. 研究发现, 高压下温度对于ZnO: Li固溶体的导电类型以及结构具有较大的影响. 其中在1500 ℃条件下烧结的ZnO: Li(Li的掺杂量4.5%)表现出良好的p型电学性能, 其电阻率为3.1× 10-1Ω·cm, 载流子浓度为3.3× 1019cm-3, 迁移率为27.7cm2·V-1·s-1. 通过实验及理论计算确定了其受主能级为110meV, 讨论了压力对p型ZnO的形成和电学性能的影响. 相似文献
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本文引入与浓度和厚度有关的kNL待定参数, 在J-O理论基础上, 对Er3+/Yb3+掺杂的LiNbO3和LiTaO3单晶衬底上 的多晶水热外延样品进行了基于吸收光谱的拟合计算. LiNbO3:Ω2=2.34× 10-20 cm2, Ω4=0.77× 10-20 cm2, Ω6=0.31×10-20 cm2, kNL=4.32× 10-2 mol·m-2. LiTaO3:Ω2=1.68×10-20 cm2, Ω4=0.84×10-20 cm2, Ω6=0.45×10-20 cm2, kNL=9.17×10-3 mol· m-2. 该方法可尝试推广到粉体或胶体等难以直接获得浓度和厚度数据的体系. 经上转换发光测试及光谱参数计分析认为Er3+/Yb3+离子的掺杂浓度比为1:1的情况下, 样品呈现绿色上转换发光光谱; 可尝试以降低基质声子能量的方法提高4I13/2能级 对2H11/2和4S3/2能级的量子剪裁效率. 相似文献
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用常压MOCVD在半绝缘GaAs衬底上生长了GaxIn1-xP(x=0.476~0.52)外延层,对外延层进行了X光双晶衍射、Hall和光致发光(PL)测试.77K下电子迁移率达3300cm2/V.s(浓度为1.4×1016cm-3).载流子浓度随生长温度升高,随Ⅴ/Ⅲ比的增大而降低,并提出P空位(Vp)是自由载流子的一个重要来源,17KPL谱中,Ga0.5In0.5P(Tg=650℃,Ⅴ/Ⅲ=70)的峰能为1.828eV,半峰宽为19meV.另外,在1.849eV处还有一较弱的峰,GaInP峰能和其计算的带隙最大相差113meV,这可能与GaInP中杂质或缺陷以及其中存在有序结构有关. 相似文献
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材料的载流子浓度和迁移率是影响器件性能的关键因素, 变温Hall测试结果证明杂质掺杂AlGaN中的载流子浓度和迁移率随温度 降低而减小.然而极化诱导掺杂的载流子浓度和迁移率不受温度变化的影响.以准绝缘 的GaN体材料作为衬底, 在组分分层渐变的AlGaN中实现的极化诱导掺杂浓度 仅仅在1017 cm-3数量级甚至更低. 本研究采用载流子浓度为1016 cm-3量级的非有意n型掺杂GaN模板为衬底, 用极化诱导掺杂技术在分子束外延生长的AlGaN薄膜材料中实现了高 达1020 cm-3 量级的超高电子浓度. 准绝缘的体材GaN半导体作衬底时, 只有表面自由电子作为极化掺杂源, 而非有意掺杂的GaN模板衬底除了提供表面自由电子外,还能为极化电场 提供更多的自由电子"源", 从而实现超高载流子浓度的n型掺杂. 相似文献
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使用最近期的EGRET/CGRO γ射线数据,确定出了中等银纬区(|b|=10°-20°)银河宇宙线与星际气体相互作用产生的γ射线的发射率q/4π,其中采用了由γ射线数据本身来确定该发射率的方法;并由此获得了以银经为函数的不同能区的逆康普顿(IC)γ射线积分强度.在该银纬区,沿银经平均的IC微分强度可表为:IIc(E)=1.58×10-6E-2.08±0.06cm-2·s-1·sr-1GeV-1,b=10°—20°;IIc(E)=2.08×10-6E-2.03±0.06cm-2·s-1·sr-1GeV-1,b=-20°—-10°,其中,能量E的范围为30MeV到4000MeV. 相似文献
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对使用金属有机物汽相沉积法生长的AlGaN/AlN/GaN结构进行的变温霍尔测量,测量结果指出在AlN/GaN界面处有二维电子气存在且迁移率和浓度在2K时分别达到了1.4×104cm2·V-1·s-1和9.3×1012cm-2,且在200K到2K范围内二维电子气的浓度基本不变,变磁场霍尔测量发现只有一种载流子(电子)参与导电.在2K温度下,观察到量子霍尔效应,Shubnikov-de Haas (SdH) 振荡在磁场约为3T时出现,证明了此结构呈现了典型的二维电子气行为.通过实验数据对二维电子气散射过程的半定量分析,推出量子散射时间为0.23ps,比以往报道的AlGaN/GaN结构中的散射时间长,说明引入AlN层可以有效减小合金散射,进一步的推断分析发现低温下以小角度散射占主导地位. 相似文献
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本文给出了刚玉中两类Fe3+离子的自旋哈密顿矩阵的普遍形式,并着重研究了当两类Fe3+离子不等价时,顺磁共振谱的特性。对于两类离子等价情况,计算了当磁场与晶轴的夹角α=0°,15°,30°,45°,54.7°,60°,75°,90°时Fe3+离子的能级。对于两类离子最不等价情况,计算了当α=10°,20°,30°,40°,50°,54.7°,60°,70°,80°时Fe3+离子的能级。并且给出了当α=0°和90°时各能级的波函数和跃迁矩阵元公式。在室温下,用ЭПР-2型波谱仪,在3厘米波段,做了蓝宝石的顺磁共振实验。利用使晶体绕两个相互垂直的方向转动的装置,精确地调整晶轴的方向。观察到了分别属于两类Fe3+离子的两套顺磁共振谱线。给出了等价及最不等价情况的等频曲线。 相似文献
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Silver-doped ZnO films were grown on glass substrates by RF reactive magnetron sputtering. The as-grown ZnO:Ag film is insulating but behaves as p-type conduction with a resistivity of 152 Ω cm, a carrier concentration of 2.24×1016 cm?3 and a Hall mobility of 1.83 cm2/V s after annealing in O2 atmosphere at 600 °C for 1 h. The influence of post-annealing temperature and ambience on the electrical, structural and optical properties of the films was investigated. 相似文献
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The properties of transparent conducting molybdenum-doped ZnO films grown by radio frequency magnetron sputtering 下载免费PDF全文
Transparent conducting molybdenum-doped zinc oxide films are prepared by radio frequency(RF) magnetron sputtering at ambient temperature.The MoO3 content in the target varies from 0 to 5 wt%,and each film is polycrystalline with a hexagonal structure and a preferred orientation along the c axis.The resistivity first decreases and then increases with the increase in MoO3 content.The lowest resistivity achieved is 9.2 × 10-4.cm,with a high Hall mobility of 30 cm2.V-1.s-1 and a carrier concentration of 2.3×1020 cm-3 at an MoO3 content of 2 wt%.The average transmittance in the visible range is reduced from 91% to 80% with the increase in the MoO3 content in the target. 相似文献
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Gang Yang Dongming Mei Jayesh Govani Guojian Wang Muhammad Khizar 《Applied Physics A: Materials Science & Processing》2013,113(1):207-213
Van de Pauw Hall measurement is an effective method to characterize the properties of semiconductors, such as bulk concentration, mobility, and resistivity, all of which are used to describe the purity level in the semiconductors. However, the performance of the ohmic contacts has a direct impact on the reliability and accuracy of the results obtained from the Van de Pauw Hall measurement. In the present work, the influences of different annealing techniques on the performance of the InSn ohmic contacts have been investigated using a High Purity Germanium (HPGe) crystal sample. The results show that the preferred annealing condition is at 400 °C for 1 hour, which has provided a significant improvement of the InSn contact quality and microscopic homogenization of the impurities in the HPGe crystal. The carrier concentration, charge mobility, and resistivity of the sample annealed at 400 °C for 1 hour are 5.772×1010/cm3, 1.883×104× cm2/Vs, and 5.795×103×Ω?cm at 77 K, respectively. 相似文献
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X. Hao J. Ma D. Zhang X. Xu Y. Yang H. Ma S. Ai 《Applied Physics A: Materials Science & Processing》2002,75(3):397-399
Transparent conducting antimony-doped tin oxide (SnO2:Sb) films were deposited on organic substrates by r.f. magnetron-sputtering. Polycrystalline films with a resistivity of
≈ 6.5×10-3 Ω cm, a carrier concentration of≈ 1.2×1020 cm-3 and a Hall mobility of ≈ 9.7 cm2 v-1 s-1 were obtained. The average transmittance of these films reached 85% in the wavelength range of the visible spectrum.
Received: 20 April 2001 / Accepted: 23 July 2001 / Published online: 17 October 2001 相似文献
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《Journal of Physics and Chemistry of Solids》2003,64(9-10):1887-1890
3 MeV electron irradiation induced-defects in CuInSe2 (CIS) thin films have been investigated. Both of the carrier concentration and Hall mobility were decreased as the electron fluence exceeded 1×1017 cm−2. The carrier removal rate was estimated to be about 1 cm−1. To evaluate electron irradiation-induced defect, the electrical properties of CIS thin films before and after irradiation were investigated between 80 and 300 K. From the temperature dependence of the carrier concentration in non-irradiated thin films, we obtained ND=1.8×1017 cm−3, NA=1.7×1016 cm−3 and ED=18 meV from the SALS fitting to the experimental data on the basis of the charge balance equation. After irradiation, a new defect level was formed, and NT0=1.4×1017 cm−3 and ET=54 meV were also obtained from the same procedure. From the temperature dependence of Hall mobility, the ionized impurity density was discussed before and after the irradiation. 相似文献
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Abstract Hall coefficient (RH) and electrical resistivity measurements have been performed as a function of temperature (between 77 K and 300 K) and under hydrostatic pressures (up to 15 kbar) on a set of Se-doped GaSb samples with impurity concentrations in the range 8×1017 cm?3 - 1×1018 cm?3. With increasing pressure at 300 K, the electrons are strongly trapped into a resonant impurity level. The pressure induced occupation of this level leads to time-dependent effects at T<120 K. The activated thermal electron emission over a potential barrier E<sb>B = 300×30 meV gives clear evidence for a large lattice relaxation around the impurity centers characteristic for DX-like behavior. 相似文献
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Effect of RF power on the properties of transparent conducting zirconium-doped zinc oxide films prepared by RF magnetron sputtering 总被引:2,自引:0,他引:2 下载免费PDF全文
Transparent and conducting zirconium-doped zinc oxide films with
high transparency and relatively low resistivity have been
successfully prepared by radio frequency (RF) magnetron sputtering
at room temperature. The RF power is varied from 75 to 150W. At
first the crystallinity and conductivity of the film are improved
and then both of them show deterioration with the increase of the RF
power. The lowest resistivity achieved is 2.07×10-3\Omegacm
at an RF power of 100W with a Hall mobility of
16cm2V-1s-1 and a carrier concentration of
1.95×1020cm-3. The films obtained are polycrystalline
with a hexagonal structure and a preferred orientation along the
c-axis. All the films have a high transmittance of approximately
92% in the visible range. The optical band gap is about 3.33eV
for the films deposited at different RF powers. 相似文献
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Work is described in which chromium-doped semi-insulating gallium arsenide has been successfully doped n-type with ion implanted silicon and sulfur, and p-type with ion implanted carbon. A dilute chemical etch has been employed in conjunction with differential Hall effect measurements to obtain accurate profiles of carrier concentration and mobility vs. depth in conductive implanted layers. This method has so far been applied to silicon-and sulfur-implanted layers in both Cr-doped semi-insulating GaAs and high purity vapor grown GaAs. In the case of sulfur implants, a strong diffusion enhancement has been observed during the annealing, presumably due to fast-diffusing, implantation-produced damage. Peak doping levels so far obtained are about 8 × 1017 electrons/cm3 for silicon implants and 2 × 1017 electrons/cm3 for sulfur implants. Mobility recovery has been observed to be complete except in regions near the surface which are heavily damaged by the implantation. 相似文献