Longitudinal stark effect in parabolic quantum dots

We present an experimental and theoretical investigation of the longitudina l quantum confined Stark effect in strain-induced parabolic InGaAs quantum dots. The electric field is applied in the plane perpendicular to the growt h axis (quantum well plane), through a sub-micron gap opened in a metallic contact, which contains just a few dots. The changes in the microphotolumin escence (mu -PL) spectra were measured versus the bias. at low temperature. Due to the device geometry, the electric field profile in the gate is not constant resulting in an asymmetric Stark effect as a function of the appli ed field polarity. Calculations of the field profile in the conatct gap and of the distorsion of the parabolic-like potential as a function of the app lied field have been made in order to correlate the observed changes in the electro-optical properties of the dots with the carrier spill over and wav efunction modifications under electric field.