Carrier-carrier scattering in photoexcited quantum wells: inadequacy of the two-particle collision model at low densities

• Published in: Semiconductor science and technology Vol. 9; no. 5S; pp. 474 - 477
• Main Authors: Cambel, V, Mosko, M
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.05.1994
• ISSN: 0268-1242; 1361-6641
• DOI: 10.1088/0268-1242/9/5S/020

Carrier-carrier scattering of a near-bandgap excited-hole plasma in an intrinsic GaAs quantum well is studied using two different Monte Carlo (MC) techniques. In the first one, the two-particle collisions are modelled using a screened Coulomb interaction. In the second one, the many-particle interaction is incorporated through classical molecular dynamics (MD). At low excitation densities (2x10 super(10) cm super(-2)) molecular dynamics gives a much slower thermalization of the plasma than the `two-particle collision' technique. This difference is ascribed to the breakdown of the two-particle collision model, because screening of Coulomb interaction at low densities is too weak to limit the range of the two-particle interaction to the mean interparticle distance. The agreement of `two-particle collision' simulations with experiment seems to be fortuitous. The disagreement of MD with experiment implies that the theory is still incomplete.