Large image potential effects in SiSrTi O3 and SiHf O 2 two-dimensional quantum well structures

Abstract

Charge image effects on the confinement properties of SiSrTi O3 and SiHf O2 two-dimensional quantum wells are studied. The combination of strong dielectric mismatch and band offset of the layers gives rise to structured confinement potentials, which can trap carriers close to the interfaces in SiSrTi O3 but not in SiHf O2 two-dimensional quantum wells. The charge image blueshifts strongly (a few hundred meV) the carrier recombination energy, comparable to the shift related to the well width shortening due to actual graded interfaces. © 2006 American Institute of Physics.