Summary: High-field transport transient of minority carriers in p-GaAs
A. M. Alencar, F. A. S. Nobre, A. J. C. Sampaio, and V. N. Freire
Departamento de Fisica, Uniuersidade Federal do Cearb, Caixa Postal 603@Fortaleza, Cear& Brazil
J. Alzamir P. da Costa
Departamento de Esica, Uniuersidade Federal do Rio Grande do Norte, 59072-Natal, Rio Grande do
(Received6 December 1990;acceptedfor publication 6 May 1991)
The time evolution of the minority electron velocity and temperaturein p-GaAs towards the
steadystate is calculated for high-electric fields and doping concentrationsof 1.5x 10"
and 1.5X lOI* cm - `. It is shown that the velocity overshootis lesspronouncedfor high doping
concentration. The electron-holeinteraction reducesthe overshooteffect, which indicates
its role in the high-field transport transient of minority carriers in p-GaAs.
The study of minority-carrier transport in dopedsemi-
conductors has considerableimportance to the design of
high-speedbipolar and heterojunction bipolar transistors.'
Severalexperimental and theoretical investigations were
performed, most of these concentrating on the steady-
state24and transient5transport propertiesof minority car-
riers in low-electric fields. It was shown, for example,that
electron-holecollisions make the holesin the n-type mate-