Absorption coefficient for the intraband transitions in quantum dot materials

Intraband transitions in quantum dot-superlattice heterostructures

Intraband carrier photoexcitation in quantum dot lasers.

We unveil the role of bound-to-continuum photoexcitation of carriers as a relevant process that affects the performance of quantum dot (QD) lasers. We present the response of an InAs/InGaAs QD laser to a sub-band gap pump, showing an unexpected depletion of the emitted photons. We relate this observation with carrier photoexcitation through additional transmission and photocurrent measurements....

Intraband absorption for normal illumination in quantum dot intermedíate band solar cells

n the current intermedíate band solar cells made with InAs quantum dots (QDs) in GaAs, the ransitions by absorption of photons between the intermedíate band and the conduction band for llumination normal to the cell surface is very weak or, more often, undetectable. We model the QD as a jarallelepiped potential well and calcúlate the envelope function of the electrón wavefunctions. By jbtaining...

Infrared spectroscopy of intraband transitions in Ge/Si quantum dot superlattices

We report the study of infrared spectroscopy of intraband transitions in Ge/Si quantum dot superlattices. The superlattices, which were grown on (001) oriented Si substrates by a solid source molecular beam epitaxy system, are composed mainly of 20 or 30 periods of Ge dot layers and Si spacer films. The structural properties of them and of the uncapped Ge dots grown on the surfaces of some of t...

Intraband Auger Effect in InAs/InGaAlAs/InP Quantum Dot Structures

T. Gebhard1, D. Alvarenga2, P.L. Souza3, P.S.S. Guimarães2, K. Unterrainer1, M.P. Pires4, G.S. Vieira5, and J.M. Villas Boas6 1Center for Micro & Nanostructures, TU, Vienna, Austria 2 Departamento de Fisica, UFMG, Belo Horizonte, Brazil 3 LabSem/CETUC, PUC, Rio de Janeiro, Brazil 4 Instituto de Fisica, UFRJ, Rio de Janeiro, Brazil 5 Divisão de Fisica Aplicada, IEA, São José dos Campos, Brazil 6...