Depth resolved studies of SrTiO3 defects using x-ray excited optical luminescence and cathodoluminescence.

We have performed comparative depth-dependent x-ray excited optical luminescence (XEOL) and depth resolved cathodoluminescence spectroscopy measurements in order to understand the native point defect distribution in three SrTiO3 samples. Both techniques found surface segregation of Ti3+ defects, but apparent differences in the oxygen vacancy distribution. Due to the lower excitation flux densities employed in XEOL, there is a delayed onset ('dead layer') revealed in the oxygen defect depth distribution, which results from band bending near the surface. By modeling the data, we are able to estimate the Ti3+ depth distribution and the depletion layer width. [ABSTRACT FROM AUTHOR]