Abstract
With infrared ellipsometry and transport measurements we investigated the electrons at the interface between and . We obtained a sheet carrier concentration of , an effective mass of , and a strongly frequency dependent mobility. The latter are similar as in bulk and therefore suggestive of polaronic correlations. We also determined the vertical concentration profile which has a strongly asymmetric shape with a rapid initial decay over the first 2 nm and a pronounced tail that extends to about 11 nm.
- Received 2 October 2009
DOI:https://doi.org/10.1103/PhysRevLett.104.156807
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