Defect segregation in CdGeAs2

Abstract

Increased axial temperature gradients and growth rates have resulted in segregation of unwanted absorbing defects to the edges of CdGeAs2 single crystals produced by the horizontal gradient freeze technique. Long-wavelength infrared imaging of polished boules revealed a “clear” central core with absorption losses 26 times lower than in the darker edge regions. This pronounced segregation is attributed to the preferred incorporation of native defects at facets that form near the side walls of the horizontal boat. EPR, GDMS, and Hall effect analysis were used to characterize the nature of these defects.