High-Field Transport and Impact Ionization in Wide Bandgap Semiconductors

High-field transport in wide bandgap semiconductors such as GaN and ZnS is currently an area of active research due to the application of such materials for visible optical sources and high temperature electronics. In many applications! the electric fields are typically much higher than those experienced by electrons and holes in conventional electronic materials due to the large bandgap of about 3.5 to 4 eV, and hence higher breakdown fields. Thus, a complete description of high-field transport including impact ionization utilizing the full band structure of these materials is critical. In the present work, we detail the results of full band structure Monte Carlo simulations of the transport properties of several such materials based on the empirical pseudopotential approach.