An improved empirical fit to Baraff´s universal curves for the ionization coefficients of electron and hole multiplication in semiconductors

Since its introduction in 1966, an empirical quadratic fit to Baraff´s curves due to Crowell and Sze, has been widely used, in conjunction with the use of Baraff´s theory to extrapolate experimental data for electron and hole ionization coefficients to conditions-notably temperature-differing from those under which those data were derived. The quality of that quadratic fit is reexamined, and an improved cubic fit is proposed.