Open Access Nano Express

Electrostatically Shielded Quantum Confined Stark Effect Inside Polar Nanostructures

Spilios Riyopoulos

Author affiliations

Science Applications International Corporation, McLean, VA, 22102, USA

Citation and License

Nanoscale Research Letters 2009, 4:993-1003  doi:10.1007/s11671-009-9347-1

Published: 30 May 2009


The effect of electrostatic shielding of the polarization fields in nanostructures at high carrier densities is studied. A simplified analytical model, employing screened, exponentially decaying polarization potentials, localized at the edges of a QW, is introduced for the ES-shielded quantum confined Stark effect (QCSE). Wave function trapping within the Debye-length edge-potential causes blue shifting of energy levels and gradual elimination of the QCSE red-shifting with increasing carrier density. The increase in the eh wave function overlap and the decrease of the radiative emission time are, however, delayed until the “edge-localization” energy exceeds the peak-voltage of the charged layer. Then the wave function center shifts to the middle of the QW, and behavior becomes similar to that of an unbiased square QW. Our theoretical estimates of the radiative emission time show a complete elimination of the QCSE at doping densities ≥1020 cm−3, in quantitative agreement with experimental measurements.