Co-reporter:Wen-qi WU, Ji-jun ZHANG, Lin-jun WANG, Jia-hua MIN, Xu-liang WEN, Xiao-yan LIANG, Jian HUANG, Ke TANG
Transactions of Nonferrous Metals Society of China 2016 Volume 26(Issue 5) pp:1433-1438
Publication Date(Web):May 2016
DOI:10.1016/S1003-6326(16)64248-6
The growth interfaces of CdMnTe (CMT) crystals grown by traveling heater method (THM) were studied. Two types of polycrystalline CMT feed ingots synthesized in a traditional rocking furnace and vertical Bridgman (VB) furnace were adopted in THM growth, and the effects of the polycrystalline feed on the growth interface were revealed. The morphology of the growth interface of CMT crystal (CMT2) grown from the feed by vertical Bridgman was smoother with lower curvature compared with that of CMT crystal (CMT1) from the feed by rocking furnace. The radial Mn composition and Te inclusion distribution of the CMT wafers were analyzed and correlated to the growth interface. The Mn segregation along the radial direction and Te inclusion density of CMT2 were lower than those of CMT1. The VB method synthesized polycrystalline feed could improve the growth interface morphology, which is beneficial for decreasing the Te inclusions and Mn segregation in CMT wafers.
Co-reporter:Min Shen, Jijun Zhang, Linjun Wang, Jiahua Min, Lin Wang, Xiaoyan Liang, Jian Huang, Ke Tang, Wei Liang, Hua Meng
Materials Science in Semiconductor Processing 2015 Volume 31() pp:536-542
Publication Date(Web):March 2015
DOI:10.1016/j.mssp.2014.12.051
Co-reporter:Jianming Lai;Linjun Wang;Jiahua Min;Wenqi Wu;Min Shen ;Wei Liang
Crystal Research and Technology 2015 Volume 50( Issue 11) pp:817-822
Publication Date(Web):
DOI:10.1002/crat.201400477
In this paper, the CdMnTe crystals were grown by the Travelling Heater Method (THM) and the Vertical Bridgman (VB) method, respectively. The crystal properties, including the Mn axial distribution, impurity concentrations, resistivity, Hall effects and energy response spectra, were characterized and compared. The results shown that the CdMnTe crystal grown by the THM had more uniform Mn distribution and lower impurity concentrations compared to the crystal grown by VB method. The resistivity of CdMnTe grown by THM was (1.5 ∼ 8) × 1010 Ω.cm, while the resistivity of CdMnTe grown by VB was 107∼108 Ω.cm. The In dopant distributed uniformly throughout the crystal ingot grown by THM with the doping concentration of 0.6–0.7 ppm, while the In dopant concentration throughout the crystal grown by VB method is in the range of 1.31–2.4 ppm. Hall measurements revealed that the conductivity of the THM grown crystal was weak n-type conductivity and the VB grown crystal was p-type conductivity. A planar CdMnTe detector from the THM grown crystal showed a resolution of 8% of the 241Am radiation at 59.5 keV peak, however, no energy response was revealed with the CdMnTe detector by the VB method. The results demonstrate that CdMnTe crystal grown by THM have better crystal quality and detector properties compared to that by VB method.
Co-reporter:Jijun Zhang;Wanqi Jie;Linjun Wang;Lijun Luan
Crystal Research and Technology 2010 Volume 45( Issue 1) pp:7-12
Publication Date(Web):
DOI:10.1002/crat.200900623
Abstract
Cd1-xMnxTe (x =0.2, CdMnTe) crystal was grown by the vertical Bridgman method, which exhibits a pure zincblende structure in the whole ingot. The major defect, twins, which is fatal to CdMnTe crystal, was analyzed with scanning electron microscopy (SEM), X-ray energy disperse spectroscopy (XEDS) and optic microscopy on the chemical etching surface. The twins observed in the as-grown ingot are mainly lamellar ones, which lie on the {111} faces from the first-to-freeze region of the ingot and run parallel to the growth axis of the ingot. Coherent twins with {115}t-{111}h orientations when indexed with respect to both the twin and host orientations, are often found to be terminated by {110}t-{114}h lateral twins. Te inclusions with about 20 μm in width are observed to preferentially decorate the lamellar twin boundaries. The origin of the twins, relating to the growth twin and the phase transformation twin, is also discussed in this paper. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Co-reporter:Gaoli Wei, Linjun Wang, Jijun Zhang, Zhenwen Yuan, Kaifeng Qin, Jiahua Min, Xiaoyan Liang, Yiben Xia
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment (11 March 2013) Volume 704() pp:127-130
Publication Date(Web):11 March 2013
DOI:10.1016/j.nima.2012.12.052
An indium-doped detector grade Cd0.9Zn0.1Te crystal was grown by the THM technique from Te-rich solution. The as-grown crystal showed the dark resistivity of (1–3)×1010 Ω cm. Through IR transmission microscopy Te inclusion with regular triangular or circular shapes could be observed, and the size of Te inclusion was around 7 μm and the concentration was ∼105 cm−3. The impurity concentrations were greatly reduced for the THM grown CZT, as compared to the Bridgman method grown CZT. A resolution of 8.5% was achieved under the 662 keV 137Cs gamma ray radiation at room temperature for the as-grown CZT samples.Highlights► Detector grade Cd1−xZnxTe has been successfully grown by the THM technique. ► The as-grown CZT has a resistivity of ∼1010 Ω cm. ► Te inclusions' size and concentration were comparable to the commercial CZT. ► A resolution of 8.5% was achieved for the 137Cs 662 keVgamma line.
Co-reporter:Xuliang Wen, Jijun Zhang, Yifei Mao, Jiahua Min, Xiaoyan Liang, Jian Huang, Ke Tang, Linjun Wang
Journal of Crystal Growth (1 April 2017) Volume 463() pp:79-85
Publication Date(Web):1 April 2017
DOI:10.1016/j.jcrysgro.2017.01.059
•The Cd0.9Mn0.1Te crystal was grown by Traveling Heater method from the In doped source ingot.•The impurity, Te inclusions and Mn composition were studied along the as-grown ingot.•The ionization energy and the concentration of point defects were revealed by the PICTS.•The mobility-lifetime product of CdMnTe:In samples was measured and discussed.The In-doped Cd0.9Mn0.1Te (CdMnTe:In) crystal was grown by the Travelling Heater Method. The crystallity of the CdMnTe:In wafers extracted from different part of the CdMnTe:In ingot was studied including the impurity contents, the Te inclusions and the Mn composition. The point defects in the CdMnTe:In wafers were revealed by the Photo-Induced Current Transient Spectroscopy (PICTS). The ionization energy, the capture cross-section and the concentration of the defect traps in different parts of the ingot were identified. The PICTS result showed the concentration of the VCd decreases from the top part to the tail part along the bulk while the concentration of A-center increase. The wafers from the middle part of the bulk were proved to have less deep level point defects compared to other parts of the crystal bulk, and had higher electronic performance with the resistivity up to 3.07 × 1010 Ω cm and the μτ value up to 1.45 × 10−3 cm2 V−1. The concentration of the deep level point defects plays an important role in the electrical properties, especially for the mobility-lifetime product.
