Energy band gaps and excited states in Si QD/SiO /R O (R = Si, Al, Zr) suboxide superlattices.

X-ray and optical spectroscopies were applied in order to study the band structure and electronic excitations of the SiO /R O (R  =  Si, Al, Zr) suboxide superlattices. The complementary x-ray emission and absorption measurements allow for the band gap values for the SiO layers to be established, which are found to have almost no dependency on the cation type R. It is determined that, after annealing, the stoichiometric factor x remains near 1.