On the electric field dependence of the conductivity of holes in Si at low temperatures. II. The influence of the variation of steady‐state hole density with electric field on the conductivity

Abstract

AbstractMeasurements of the electric field dependence of the hole conductivity of Si with various doping levels and orientations are performed at 20.3 and 27.1 K. A description of the essential characteristics of the experimental results is achieved within the frame of a theoretical model. In this model, the field dependence of the hole mobility (taking into account non‐parabolicity of the valence band and non‐equipartition of acoustic phonon energy in the distribution function as well as in the momentum relaxation time) and the field dependence of the hole concentration (based on Lax′ cascade theory) are combined. Comparison of experimental and numerical results gives the relation between the participation of optical phonons in the hole capture process on shallow acceptors and the transition from super‐ to sublinear current‐voltage characteristics in high‐purity p‐Si at low temperatures and at electric field strengths below the breakdown range.