Spectroscopy of the interaction between nitrogen and hydrogen in ZnSe epitaxial layers

摘要

We report on detailed optical-spectroscopy investigations of nitrogen-doped ZnSe epitaxial layers of various doping levels and N contents which have been exposed ex situ to a hydrogen/deuterium plasma. The influence of this treatment is studied through temperature-dependent photoluminescence and selective photoluminescence. The results are similar for all samples, irrespective of their doping properties. We show that the Ns, acceptor is strongly passivated and that the deep compensating-donor disappears after plasma exposure. In addition, the nature of the main shallow compensating-donor is changed by the HID treatment. The shallow donor in ZnSe:N which we have previously identified as a N-related defect is suppressed while the usual residual impurities of ZnSe are uncovered. Our results directly demonstrate that all compensating donors in ZnSe:N material are N-related defects, and that N may participate to nonradiative recombination centers at heavy doping. Finally, this helps selecting a few models for the deep compensating-donor and further support the implication of N interstitials in carrier compensation in ZnSe:N. [References: 42]