Crystal growth and characterization of Cd0.8Mn0.2Te using Vertical Bridgman method

By Vertical Bridgman method, several Cd{sub 0.8}Mn{sub 0.2}Te (CdMnTe) ingots were grown. The structure and crystallinity of the ingots were evaluated by X-ray powder diffraction and double-crystal rocking curve measurement and etch pits density (EPD) measurement. The results showed a pure cubic zinc blende structure throughout the ingots with the full width at half maximum (FWHM) of 40-70 arcsec and EPD of (6-8) x 10{sup 4} cm{sup -2}, indicating a high crystalline perfection. The Mn concentration distribution along the axial and radial direction of the ingots was measured by inductively coupled plasma atomic emission spectrometer (ICP-AES). The segregation coefficient k{sub eff} for Mn along the axis of the ingots is determined to be 0.95, and the radial variation of Mn concentration is within 0.002. Current-voltage (I-V) measurement reveals that sputtered Au film can form good ohmic contact to CdMnTe wafer and all the wafers of the as-grown crystals have the resistivity within (1-4) x 10{sup 6} {omega} cm. IR transmission measurement in the wave number region from 4000 to 1000 cm{sup -1} exhibits that the IR transmittance of CdMnTe wafers is 50-55%, which is close to the theoretical value.