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

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 (5.6-5.7 eV) yielding the conduction and valence band offsets at the Si/oxide interface of 2.0+/-0.1 and 2.5+/-0.1 eV, 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. (C) 2004 American Institute of Physics.