PHOTOLUMINESCENCE OF VAPOR AND SOLUTION-GROWN ZNTE SINGLE-CRYSTALS

ZnTe single crystals grown by horizontal physical vapor transport (PVT ) and by vertical traveling heater method (THM) from a Te solution wer e characterized by photoluminescence (PL) at 10.6 K and by atomic forc e microscopy (AFM). Copper was identified by PL as a major impurity ex isting in both crystals, forming a substitutional acceptor, Cu(Zn). Th e THM ZnTe crystals were found to contain more Cu impurity than the PV T ZnTe crystals. The formation of Cu(Zn)-V(Te) complexes and the effec ts of annealing, oxygen contamination and intentional Cu doping were a lso studied. Finally, the surface morphology analyzed by AFM was corre lated to the PL results.