This paper compares and contrasts different theoretical approaches based on incoherent electron scattering transport with experimental measurements of optoelectronic devices formed from semiconductor heterostructures. The Monte Carlo method which makes no a priori assumptions about the carrier distribution in momentum or phase space is compared with less computationally demanding energy-balance rate equation models which assume thermalised carrier distributions. It is shown that the two approaches produce qualitatively similar results for hole transport in p-type Si_1-xGe_x/Si superlattices designed for terahertz emission. The good agreement of the predictions of rate equation calculations with experimental measurements of mid- and far-infrared quantum cascade lasers, quantum well infrared photodetectors and quantum dot infrared photodetectors substantiate the assumption of incoherent scattering dominating the transport in these quantum well based devices. However, the paper goes on to consider the possibility of coherent transport through the density matrix method and suggests an experiment that could allow coherent and incoherent transport to be distinguished from each other.

Date Published: 29 January 2008
PDF: 15 pages
Proc. SPIE 6909, Novel In-Plane Semiconductor Lasers VII, 690912 (29 January 2008); doi: 10.1117/12.762648

Published in SPIE Proceedings Vol. 6909:
Novel In-Plane Semiconductor Lasers VII
Alexey A. Belyanin; Peter M. Smowton, Editor(s)