Shot-noise in non-degenerate semiconductors with energy-dependent elastic scattering

Abstract

We investigate current fluctuations in non-degenerate semiconductors, on length scales intermediate between the elastic and inelastic mean free paths. The shot-noise power P is suppressed below the Poisson value P_{\rm Poisson}=2e\bar I (at mean current \bar I) by the Coulomb repulsion of the carriers. We consider a power-law dependence of the elastic scattering time \tau\propto\epsilon^{\alpha} on kinetic energy \epsilon and present an exact solution of the non-linear kinetic equations in the regime of space-charge limited conduction. The ratio P/P_{\rm Poisson} decreases from 0.38 to 0 in the range -1/2 < \alpha < 1.