Growth and characterization of In doped Cd_0.8Mn_0.2Te single crystal

The Cd_1-xMn_xTe crystal is believed to be a good candidate to compete with Cd_1-xZn_xTe in the X-ray and γ-ray detector application. In this paper, we present the growth of indium (In) doped Cd_0.8Mn_0.2Te (CdMnTe:In) ingot by the vertical Bridgman method. The crystalline structure and quality was verified by X-ray diffraction and double-crystal rocking curve measurement and etch pits density measurement (EPD). The results showed a pure cubic zinc blende structure throughout the ingot with the FWHM of 40-80 arcsec and EPD of 10⁴-10⁵ cm^-2, indicating a high crystalline perfection. The In dopant distribution in the ingot was analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS). The segregation coefficient of In in CdMnTe was evaluated to be 0.075. The effects of In-doping on the properties of CdMnTe single crystal were analyzed. Current-voltage (I-V) measurement reveals that CdMnTe:In has the resistivity 1-3×10⁹ Ω cm, which is three orders higher than undoped CdMnTe. IR transmission measurement exhibits that In-doping results in remarkable reduction of IR transmittance of CdMnTe crystal due to lattice absorption.