Efeito da exitação no espectro de emissão de multiplos poços quanticos (GaAs/ALxGa1-xAs) com dopagem modulada

AUTOR(ES)
DATA DE PUBLICAÇÃO

1989

RESUMO

We have studied the photoluminescence of a GaAs/AlxGa1-xAs Asymmetric Modulation Doped Multiple Quantum Well (AMDMQW) structure. The spectra show an emission line at 1.526 eV, when the sample is excited by Kr+ laser, which corresponds to a transition in the Wells. Under similar excitation conditions by Ar+ laser, we observed the manifestation of the Permanent, Photoconductivity Effect which provides the filling of the second electron sub-band. In this case we observed two lines, at 1.527 eV and 1.545 eV, coming from the GaAs wells. In both cases (Kr+ and Ar+) these lines shift, toward higher energies as the excitation intensity increases. From our results we conclude that the lines at 1.527 (1.626 eV) and 1.545 eV correspond to transitions due to the recombination of the two dimensional electron gas (2DEG) confined in two different sub-bands and that the second one is a break down of the selection rule for transitions between sub-bands. We conclude too that the mentioned shift represents a decrease in the 2DEG density, which is explained in the base of a transference of photoexcited holes in the barrier to the GaAs quantum Wells

ASSUNTO(S)

fotoluminescencia semicondutores - dopagem

ACESSO AO ARTIGO

Documentos Relacionados