Electron scattering in InP and GaAs and its variation with temperature and impurity concentration

Abstract

We report measurements of the pressure dependence of the electron mobility in InP and GaAs over a temperature range from 4-300K. Increasing pressure causes an increase in the direct band-gap and a corresponding increase in the electron effective mass. This can be used to investigate the important free carrier scattering mechanisms through their characteristic dependence on effective mass. In particular we will describe how this has allowed identification of impurity band conduction as playing a significant role over quite a wide range of intermediate doping densities. This results in a modified pressure dependence of the electron mobility. The important consequences of these effects are discussed.

Key Words:

• Electron mobility
• InP
• GaAs
• pressure dependence