Strong in-plane polarized intraband absorption in vertically aligned InGaAs/GaAs quantum dots
- 19 May 2003
- journal article
- Published by AIP Publishing in Applied Physics Letters
- Vol. 82 (20) , 3415-3417
- https://doi.org/10.1063/1.1575931
Abstract
We present a midinfrared absorption study of an n–i–n structure containing two planes of strongly coupled In0.5Ga0.5As self-assembled quantum dots. We find that the dominant absorption occurs for light polarized in the growth plane (E//xy), contrasting with uncoupled dots which exhibit stronger absorption for light polarized in the growth direction (E//z) in the same energy range. Results from the coupled dot sample indicate that the confinement length in the growth direction is increased, lowering the energy of the s-like ground state and hybridizing px,y-like excited states and wetting layer states. A significantly increased normal incidence photocurrent signal is measured for the sample containing coupled dots, relative to samples containing up to 30 layers of uncoupled dots, confirming the enhancement of the normal incidence absorption.Keywords
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