Band alignment between (100)Si and complex rare earth∕transition metal oxides

Abstract

The electron energy band alignment between (100)Si and several complex transition∕rare earth (RE) metal oxides (LaScO3, GdScO3, DyScO3, and LaAlO3, all in amorphous form) is determined using a combination of internal photoemission and photoconductivity measurements. The band gap width is nearly the same in all the oxides (5.6–5.7eV) yielding the conduction and valence band offsets at the Si∕oxide interface of 2.0±0.1 and 2.5±0.1eV, respectively. However, band-tail states are observed and these are associated with Jahn-Teller relaxation of transition metal and RE cations which splits their d* states.