共查询到16条相似文献,搜索用时 59 毫秒
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采用移动加热器法生长铟惨杂浓度为5×1017 atoms/cm3的Cd0.9Mn0.1Te (CMT)和Cd0.9Zn0.1Te (CZT)单晶.生长得到的CMT晶体和CZT晶体电阻率范围为4.5×109 ~ 6.2×1010 Ω·cm.CMT晶体的成分均匀性要优于CZT晶体,拟合得到CMT和CZT晶体中Mn和Zn的分凝系数分别为0.95和1.23.富Te区在两种晶体生长过程中都具有显著的提纯作用,In惨杂的浓度范围均在6.4 ~ 14.4 ppm范围内.红外透射显微镜观察到三角形和六边形为主的Te夹杂的尺寸5 ~24 μm,浓度为105 cm-3.除最后结晶区之外,沿晶体生长方向Te夹杂的尺寸逐渐减小而浓度逐渐增大.制备的CMT和CZT探测器对59.5 keV241Am放射源均有能谱响应,能量分辨率分别为23.2;和24.6;. 相似文献
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采用垂直布里奇曼法(VB)生长CdMnTe晶体,由于生长温度高、堆垛层错能低、热应力大等因素,晶体中存在大量孪晶、杂质、夹杂相等,限制其在核辐射探测器方面的应用.为了提高晶体的质量,本文采用移动加热器法(travelling heater method,THM)生长CdMnTe晶体,对该方法生长的晶体中Mn的轴向分布、杂质浓度、Te夹杂和电学性能进行测试分析,并与VB法生长的晶体作对比.结果表明THM法生长的CdMnTe晶体中Mn的轴向分布均匀,杂质浓度低于VB法制得的晶体,Te夹杂的尺寸5~25 μm,浓度105 cm-3,电阻率为109~1010Ω·cm,导电类型为弱n型,制备的探测器在室温下对241Am放射源有能谱响应.实验表明THM法生长的CMT晶体在晶体质量和电学性能方面明显优于VB法. 相似文献
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采用加速坩埚旋转技术-Bridgman(ACRT-B)法制备了φ40 mm的结构较为完整的Cd0.96Zn0.04Te晶锭.利用红外分光光度计测定晶片的近红外透射曲线,最大斜率切线法测定截止波长(cut-off wavelength,threshold wavelength),进而计算截止能量和该点的Zn组份.绘制了晶片表面的组织图,以及晶锭轴向剖面的Zn组份等高线图.实验结果表明:ACRT方法显著改善晶体组份的轴向偏析和径向偏析,晶锭中部存在两个Zn组份轴向和径向皆均匀的区域,分别约占晶锭体积的37;和16;,对应于两个大的单晶晶粒,大部分区域Zn组分径向偏析几乎完全消失. 相似文献
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Thermal conditions and rotation rate were examined experimentally for obtaining a flat interface growth of high melting‐point oxide (Tb3ScxAl5‐xO12 ‐ TSAG) by the Czochralski method. The critical crystal rotation rate can be significantly reduced, of about twice at low and very low temperature gradients comparing to medium temperature gradients in the melt and surroundings of the crystal. The interface shape of TSAG crystals is not very sensitive on crystal rotation rate at small rotations and becomes very sensitive at higher rotations, when the interface transition takes place. The range of crystal rotation rates during the interface transition from convex to concave decreases with a decrease of temperature gradients. At low temperature gradients interface inversion crystals takes place in very narrow range of rotation rates, which does not allow one to growth such crystals with the flat interface. Even changing crystal rotation rate during the growth process in a suitable manner did not prevent the interface inversion from convex to concave and thus did not allow to obtain and maintain the flat interface. 相似文献
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本文使用金刚石磨料作为晶种颗粒,通过热丝化学气相法生长出单晶金刚石颗粒,并且建立三维的有限元模型,利用有限元仿真分析了生长过程中影响金刚石磨料生长速率以及沉积质量的各种因素,如热丝的排列方式,衬底的温度场,以及晶种的分布方式.通过固定在热丝CVD反应腔里的热电偶测量了实际的衬底温度分布,从而验证了仿真结果的正确性.另外,通过改变仿真模型优化了沉积单晶金刚石颗粒的工艺参数,获得适应于合成单晶金刚石颗粒的新技术,为化学气相沉积合成单晶金刚石颗粒奠定了基础,也为高温高压金刚石磨料品级的改进与提高提供了新途径. 相似文献
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Some observations made on the nature and distribution of monolayer (elementary) steps on the (100) cleavage faces of MgO single crystals by atomic force microscopy are presented and discussed. The following types of patterns of monolayer steps are described: (1) trains of steps, (2) steps terminating on the cleaved surface at the emergence points of screw dislocations, and (3) localized pinning of advancing steps at random sites (probably at the emergence points of edge dislocations). It is shown that: (1) the origins of emergence points of monolayer steps are devoid of hollow cores due to a small Burgers vector of dislocations and (2) the minimum distance between two emerging steps due to screw dislocations and between two pinning centres due to edge dislocations depends on their sign, and is determined by the mutual interaction between neighbouring dislocations. 相似文献