Impact Ionization in ZnS

TL;DR

This paper calculates the impact ionization rate in ZnS, highlighting the importance of orientation dependence and screening effects, and provides a practical formula for energy-dependent transition rates.

Contribution

It introduces a detailed calculation of impact ionization in ZnS, emphasizing the role of orientation dependence and screening, along with a simple fit formula for transition rates.

Findings

Strong correlation between ionization rate and band structure

Orientation dependence significantly affects ionization rates

Screening function is essential for accurate calculations

Abstract

The impact ionization rate and its orientation dependence in k space is calculated for ZnS. The numerical results indicate a strong correlation to the band structure. The use of a q-dependent screening function for the Coulomb interaction between conduction and valence electrons is found to be essential. A simple fit formula is presented for easy calculation of the energy dependent transition rate.