Mesoscopic capacitor effect in GaN/AlGaN quantum wells

We show that wide GaN quantum wells behave like mesoscopic capacitors. The electron-hole pairs, are separated by the spontaneous and piezoelectric polarization fields and accumulated in the well. resulting in a well width dependent screening of the built-in field. The extent to which such screening is effective depends on the non-radiative recombination probability which depletes the ground level of the quantum well, causing the recovery of the unscreened built infield. The account of the mesoscopic capacitor effect provides a quantitative description of the optical spectra of a set of high quality quantum wells, with well characterized structural parameters.