Original scientific paper
Electron and hole impact ionization coefficients at very high electric fields in semiconductors
Abou El-Ela
; Department of Physics, Faculty of Girls, Ain Shams University, Heliopolis, Cairo, Egypt
I. M. Hamada
; Department of Physics, Faculty of Science, Tanta University, Tanta, Egypt
Abstract
We have fitted the soft lucky drift model of impact ionization of Ridley to experimental data for GaAs, InP, Si, Ge and In0.47Ga0.53As semiconductors. Excellent fits of the theory to experimental data were obtained by using least-squares fitting algorithm. A generalized Keldysh formula has been used to introduce a soft threshold factor. Generalized Keldysh formula originates from realistic energy bands in semiconductors at high electric field which reflects the density of states of energy bands. Keldysh factor and a new mean free path are calculated. A comparison with reported values of both Ridley and Marsland showed reasonable agreement for mean free path, but there are still large differences among Keldysh factors.
Keywords
semiconductors; impact ionization; high field transport; GaAs; InP; Ge; Si; In0.47Ga0.53As
Hrčak ID:
301745
URI
Publication date:
1.7.2004.
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