Modeling of Carrier and Phonon Spectrum in Quantum Dot Superlattices for Optoelectronic and Thermoelectric Applications
O.L. Lazarenkova and A.A. Balandin
Department of Electrical Engineering, US
Keywords: quantum dot superlattices, phonon spectrum modification
Quantum dot superlattices, e.g. multiple arrays of quantum dots, have been proposed for optoelectronic and thermoelectric applications. In this paper we present two models for calculating carrier spectrum in regimented three-dimensional (3D) quantum dot superlattices and perform model-based structure optimization for specific applications. To find the carrier spectrum we solve Schrödinger equation using two different approaches. In the first one, we use a model confining potential that allows for carrier wave function separation and semi-analytical solution. In the second approach, we solve the equation directly using the finite-difference method. We find good agreement of the results for the below-the-barrier states, which validates further use of the simplified semi-analytical model for carrier transport and optical spectrum calculations. The acoustic phonon dispersion in quantum dot superlattices is found from the solution of the elasticity equation by the finite-difference method. Our results indicate strong modification of phonon dispersion in such nanostructures. The latter affects electron ? phonon scattering rates and modifies carrier transport in such structures.
1. K.L. Wang and A.A. Balandi in Optics of Nanostructured Materials, edited by V. Markel and T. George (John Wiley & Sons, New York, 2000), p. 515.
2. O.L. Lazarenkova and A.A. Balandin, J. Appl. Phys., 89, 5509 (2001).
NSTI Nanotech 2003 Conference Technical Program Abstract