Spectroscopic evidence and control of compensating native defects in dopedZnSe

Electron paramagnetic resonance spectroscopy combined with photoexcitation is used to identify and characterise the defects responsible for the compen sation in iodine or aluminium doped ZnSe bulk crystals. The principal g-val ues of the AlZnVZn complex are reported for the first time. The acceptor le vels of both A-centres observed are determined at 0.50 and 0.54 eV above th e valence band edge for ISeVZn and AlZnVZn, respectively. Annealing of thes e samples in Zn vapour is shown to br suitable for reproducible adjustments of the electron concentration at room temperature up to a few 10(18) cm(-3 ). The tight coupling of these vapour phase equilibrations with the electri cal and spectroscopic analysis allows to propose a simple defect-chemical m odel. (C) 2001 Elesvier Science B.V. All rights reserved.