Scanning electron microscopy characterization of ZnSe single crystals grown by solid-phase recrystallization

Abstract

ZnSe single crystals were grown from n-type microcrystalline boules by a Solid Phase Recrystallization (SPR) method. The recrystallizations were performed under different atmospheres, Ar or Se, and pressures to investigate the influence of growth conditions on the structural features of the resulting crystals. The samples were mechanically and mechano-chemically polished in a bromine methanol solution and, then, etched in HCl for a short time, before characterization. The homogeneity and the nature of defects in the crystals were studied by Cathodoluminescence (CL) in the scanning electron microscope (SEM). CL measurements show the existence of slip bands in the recrystallized samples, likewise CL spectra show that on these samples the dislocation related Y band is enhanced and the emission bands appearing in the 2.0-2.5 eV region depend on the annealing conditions. In addition during SPR, twinned regions appear with different electronic recombination properties.