Open Access Nano Express

Origin of the blueshift of photoluminescence in a type-II heterostructure

Masafumi Jo124*, Mitsuru Sato1, Souta Miyamura1, Hirotaka Sasakura1, Hidekazu Kumano1 and Ikuo Suemune13

Author Affiliations

1 RIES, Hokkaido University, Kita-21, Nishi-10, Sapporo, 001-0021, Japan

2 Japan Society for the Promotion of Science (JSPS), 1-8, Chiyoda-ku, Tokyo, 102-8472, Japan

3 Japan Science and Technology Corporation (CREST), Saitama, 332-0012, Japan

4 Photonic Materials Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki, 305-0047, Japan

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Nanoscale Research Letters 2012, 7:654  doi:10.1186/1556-276X-7-654

Published: 27 November 2012

Abstract

Blueshifts of luminescence observed in type-II heterostructures are quantitatively examined in terms of a self-consistent approach including excitonic effects. This analysis shows that the main contribution to the blueshift originates from the well region rather than the variation of triangular potentials formed in the barrier region. The power law for the blueshift, ΔEPL ∝ Plaserm, from m = 1/2 for lower excitation Plaser to m = 1/4 for higher excitation, is obtained from the calculated results combined with a rate equation analysis, which also covers the previously believed m = 1/3 power law within a limited excitation range. The present power law is consistent with the blueshift observed in a GaAsSb/GaAs quantum well.

Keywords:
Quantum well; type-II; Blueshift; Excitons; GaSb; GaAs; Photoluminescence; 71.35.-y: Excitons; 78.55.Cr: Photoluminescence of III-V semiconductor; 81.15.Hi: Molecular beam epitaxy