共查询到11条相似文献,搜索用时 46 毫秒
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GaAs单晶是当前光电子器件的主要衬底材料之一,在红外LED中有着重要应用。但杂质浓度高、迁移率低等缺点会严重影响红外LED器件性能。为生产出低杂质浓度、高迁移率、载流子分布均匀、高利用率的红外LED用掺硅垂直梯度凝固(VGF)法GaAs单晶,本文研究了热场分布、合成舟和炉膛材质、工艺参数对单晶的成晶质量、杂质浓度、迁移率、载流子分布的影响。利用CGSim软件对单晶生长热场系统进行数值模拟研究,温区一至温区六长度比例为8∶12∶9∶5∶5∶7时,恒温区达到最长,位错密度达到1 000 cm-2以下,成晶率达到85%。采用打毛石英合成舟进行GaAs合成,用莫来石炉膛替代石英炉膛,可以获得迁移率整体高于3 000 cm2/(V·s)的GaAs单晶,满足红外LED使用要求。对单晶生长工艺参数展开研究,采用提高头部生长速度、降低尾部生长速度的方式提高单晶轴向载流子浓度均匀性,头尾部载流子浓度差降低33%,尾部迁移率从2 900 cm2/(V·s)提高到3 560 cm2/(V·s)。单晶有效利用长度提高33... 相似文献
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采用垂直布里奇曼法(VB法)生长2英寸GaSb单晶,分析了GaSb多晶产生的原因,即GaSb原料与覆盖剂中残留水分发生化学反应生成氧化镓残渣,残渣吸附在坩埚内壁导致GaSb多晶形成.通过增加覆盖剂除水工艺,成功生长出2英寸高质量GaSb单晶.此外,研究了单晶内部位错分布特点,结果显示GaSb晶体具有较低的位错密度,EPD≤500 cm-2;同时,对晶体进行XRD摇摆曲线测试,其FWHM值为27 arcsec,表明晶体质量较高;此外,对晶体进行了电学性能测试,结果显示制备的GaSb晶体呈P型导电,晶体迁移率为610 cm2/V·s,载流子浓度达到了1.68×1017cm-3. 相似文献
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L. C. Nistor S. V. Nistor V. Teodorescu I. Voicu 《Crystal Research and Technology》1979,14(12):1525-1528
Single crystals of CaF2 doped with ThO2 were grown by the Czochralski-Kyropoulos technique in graphite crucibles. The distribution of thorium in the as grown crystals has been investigated by optical and transmission electron microscopy, selected area diffraction and optical spectroscopy. 相似文献
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Infrared reflectivity spectra of thermally oxidized CuInSe2 single crystals are measured at room temperature in the wavenumber range from 180 to 4000 cm−1. A Kramers-Kronig analysis of the spectra reveals seven vibrational modes with frequencies which agree with mode frequencies in In2O3. No vibrational modes due to Cu–O and Se–O bonds could be observed. The results obtained are compared with previous studies of oxidized CuInSe2 crystals. 相似文献
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EPR and optical absorption studies have been made on anthracene single crystals irradiated with electrons at liquid nitrogen temperature. Studies of annealing of the EPR spectra induced by irradiation at liquid nitrogen temperature revealed that they consisted of a broad singlet and two sets angular dependent lines. The angular dependence of the latter was studied and they were ascribed to the 9- and 1-dibenzo-cyclohexadienyl radicals. From comparison of the change in the EPR spectra with the change in the optical absorption spectra at room temperature, optical absorption bands at 535 and 675 nm were ascribed to 9- and 1-dibenzo-cyclohexadienyl radicals. An optical absorption band at 645 nm, which is created by irradiation at liquid nitrogen temperature and decays within two hours at room temperature was suggested to arise from the 2-dibenzo-cyclohexadienyl radical. The broad singlet, which is annealed below room temperature, was ascribed to the 9-anthracyl radical. 相似文献
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H. Schmidt T. Fleischer B. Sumpf A. Szczerbakow Ka. Herrmann J. W. Tomm 《Crystal Research and Technology》1991,26(6):757-766
Results on applied infrared photoluminescence investigations of lead salt chalcogenides are presented. Interpretations of spectra and wafer maps are given. The results obtained may be applied to the investigation of material properties important for laser and detector fabrication. 相似文献