Deep hole trap properties of <i>p</i>-type ZnSe grown by molecular beam epitaxy

Abstract

The characteristics of deep hole traps in p-type ZnSe are studied by means of a transient capacitance spectroscopy technique. p-type ZnSe layers were grown by molecular beam epitaxy using radical N2 (nitrogen) doping. A major deep hole trap with a thermal hole activation energy of ΔE=720±30 meV is detected for two different sample structures: (a) n+-p ZnSe diodes and (b) Au-p ZnSe double-Schottky diodes. The trap concentration tends to increase as the net acceptor (N) concentration increases. The deep hole trap has revealed an exponential temperature dependence of hole capture rates, indicating a strong electron-lattice coupling in carrier capture/emission processes.