Lookup NU author(s): Dr Jonathan Mar
This is the final published version of an article that has been published in its final definitive form by AIP Publishing LLC, 2011.
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We perform excitation-intensity-dependent measurements of the neutral exciton (X0) photocurrent (PC) peak amplitude from a single InAs/GaAs self-assembled quantum dot (QD) embedded in the intrinsic region of an n-i-Schottky photodiode. Since resonant laser-excitation of the X0 transition cannot occur until the comparatively slow hole tunnels out of the QD, we observe a saturation of the PC peak amplitude towards high excitation-intensities, allowing us to determine the hole tunnelling time by fitting with an appropriate theoretical model. By repeating this measurement for a range of bias voltages, we obtain the hole tunnelling time as a function of vertical electric field, showing that it can be tuned by nearly two orders of magnitude. Finally, we find that the hole tunnelling rate can be described accurately by a theoretical model based on a Wentzel-Kramers-Brillouin approximation to yield precise values for the QD height and hole confinement potential.
Author(s): Mar JD, Xu XL, Baumberg JJ, Irvine AC, Stanley C, Williams DA
Publication type: Article
Publication status: Published
Journal: Applied Physics Letters
Online publication date: 18/07/2011
Date deposited: 15/06/2020
ISSN (print): 0003-6951
ISSN (electronic): 1077-3118
Publisher: AIP Publishing LLC
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