A modified vertical bridgman method for growth of high-quality Cd _1-xZr_xTe crystals

In order to deal with the phenomena of Cd evaporation from the raw materials and the heterogeneity caused by the larger-than-unity segregation coefficient of Zn in CdTe during the conventional vertical Bridgman method (VBM) growth of Cdl-xZnxTe (CZT), two modifications - Cd compensation and accelerated crucible rotation technique (ACRT) - are simultaneously adopted to the VBM. By a combination of VBM with the two modifications, several CZT ingots with the dimensions of ∼60 × 150 mm² are grown. Structural, optical, and electrical characterization of the as-grown CZT crystals reveals that the application of Cd compensation and ACRT is of obvious efficiency in improving concentration homogeneity, reducing defect density, raising crystal quality and, therefore, upgrading the optoelectronic properties of CZT crystals. Nuclear spectra measurements of detectors fabricated from the as-grown crystals also indicate that both modifications can upgrade the detecting performance of CZT.