Hyperfine Interactions in the Electron Paramagnetic Resonance Spectra of Point Defects in Wide-Band-Gap Semiconductors.

摘要

The focus of this research was to acquire definitive experimental data on predominant point defects in three important wide-band-gap semiconductors. Hyperfine interactions in electron paramagnetic resonance spectra were used to characterize the neutral nitrogen acceptor in zinc oxide, to identify a silicon interstitial impurity in titanium dioxide, and to determine the electronic structure of the singly ionized sulfur vacancy in stannous hexathiohypodiphosphate (SPS). Research on the basic properties of these technologically important materials plays a crucial role in the development of advanced optical and electronic systems. Zinc oxide is an electro-optic material with the potential to produce highperformance electronics and also ultraviolet detectors and emitters. The angular dependencies of axial and basal 67Zn hyperfine lines were used to extract 67Zn hyperfine interaction parameters for the neutral nitrogen acceptor in zinc oxide. These data establish the exact nature of the ground-state wave function associated with this important acceptor. The experimental information obtained in this study about the ground-state wave function will allow computational theorists to model the nitrogen acceptor and determine whether it can successfully lead to p-type conduction in zinc oxide. The search for p-type zinc oxide is one of the most important basic questions in present-day research on wide-band-gap semiconductors.