Abstract
New information on the electron-hole wavefunctions in InAs-GaAs self-assembled quantum dots is obtained from study of the quantum confined Stark effect. From the sign of asymmetry observed in the Stark effect, it is deduced that the dots have a permanent dipole moment directed from base to apex, implying that holes are localised above the electrons in the dots. This highly unexpected electron-hole alignment is opposite to that predicted by all previous theories. We explain our results by comparison with strain/electronic structure modelling, and are able to deduce that the nominally InAs dots contain significant amounts of gallium, and have a strongly truncated shape. In the light of these results most if not all previous modelling of the electronic structure of InAs self-assembled quantum dots needs to be re-examined. The mechanisms involved in the photocurrent process employed to observe the Stark effect, and the significance of photocurrent techniques to measure absorption spectra in quantum dots are discussed.
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Skolnick, M.S. et al. (2000). The Stark Effect and Electron-Hole Wavefunctions in InAs-GaAs Self-Assembled Quantum Dots. In: Sadowski, M.L., Potemski, M., Grynberg, M. (eds) Optical Properties of Semiconductor Nanostructures. NATO Science Series, vol 81. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-4158-1_35
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DOI: https://doi.org/10.1007/978-94-011-4158-1_35
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