Process Parameters Optimization for Cd0.9Zn0.1Te Crystal Grown by Traveling Heater Metho

doi:10.15541/jim20160658

Abstract

Abstract:

To overcome the shortages of high growth temperature, low single crystal ratio and inhomogeneous composition of Cd_0.9Zn_0.1Te(CZT) crystal growth, the In-doped CZT crystal was grown by traveling heater method through optimized growth process parameters. High quality CZT crystals with diameter of 45 mm were grown after optimizing crystal growth temperature, temperature gradient at solid-liquid interface and in-situ annealing process, which had high resistivity, high transmittance, excellent uniformity, and low concentration of Te inclusions. Moreover, the patterns of wafer and powder X-ray diffraction showed that the crystallinity and the segregation of CZT were improved. Infrared transmittance spectra indicated that the level of impurities and defects was low in the crystal and the overall infrared transmittance of the crystal was about 60%. And UV-visible light absorption spectrum presented good uniformity of the crystal. Te inclusions in the crystal were observed by Infrared microscope, and it was found that Te inclusions were mainly distributed between 0-10 μm. In addition, mobility-life product for electrons of the crystal obtained was 8×10^-4cm²/V by direct current photoconductivity technique.

Key words: traveling heater method, Cd0.9Zn0.1Te, infrared transmittance, direct current photoconductivity

CLC Number:

TQ174

LING Yun-Peng, MIN Jia-Hua, LIANG Xiao-Yan, ZHANG Ji-Jun, YANG Liu-Qing, WEN Xu-Liang, ZHANG Ying, LI Ming, LIU Zhao-Xin, WANG Lin-Jun, SHEN Yue. Process Parameters Optimization for Cd_0.9Zn_0.1Te Crystal Grown by Traveling Heater Metho[J]. Journal of Inorganic Materials, 2017, 32(9): 980-984.

Figures/Tables 8

Fig. 1 CZT crystal appearance grown by THM method

Fig. 2 XRD patterns of CZT crystal powder distributed in different axial positions

Fig. 3 Typical XRD pattern of CZT crystal wafer

Fig. 4 Infrared transmission spectrum of CZT wafers distributed in different axial positions

Fig. 5 Ultraviolet light-visible light absorption spectrums distributed in different axial positions

Fig. 6 Typical infrared microscopic image for CZT crystal

Fig. 7 I-V curve of CZT wafer tested in darkness

Fig. 8 Normalized photocurrent-voltage curves of electron and hole fitted by Hecht formula

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