Crystal growth of large-diameter bulk CdTe on GaAs wafer seed plates

We report here on some of the characteristics of CdTe bulk crystals grown on commercially available (211)B GaAs wafers by multitube physical vapour transport, a process analogous to vapour phase heteroepitaxy. Crystals several millimetres in thickness have been grown on 50 mm diameter seed plates with growth rates similar to 120 mu m/h. Double- and triple-axis X-ray diffraction gave resolution-limited FWHM values of 34 arcsec. Maps across an as-grown surface showed the FWHM to be less than similar to 80 arcsec over the majority of the surface. Infrared microscopy revealed there were comparatively low levels of Te inclusions in the central part of the crystal, but rather higher concentrations towards the edges. The use of GaAs substrates did not appear to produce the compensated material, and it was necessary to dope the material with Cl to render it semi-insulating. (c) 2007 Elsevier B.V. All rights reserved.