"Electronic structure of delta-doped La:SrTiO3 layers by hard x-ray photoelectron spectroscopy "

A. M. Kaiser: A. X. Gray, G. Conti, B. Jalan, A. P. Kajdos, A. Gloskovskii, S. Ueda, Y. Yamashita, K. Kobayashi, W. Drube, S. Stemmer, and C. S. Fadley; Appl. Phys. Lett., 06/27/12.

Additional Authors: A. X. Gray, G. Conti, B. Jalan, A. P. Kajdos, A. Gloskovskii, S. Ueda, Y. Yamashita, K. Kobayashi, W. Drube, S. Stemmer, and C. S. Fadley

Abstract:

We have employed hard x-ray photoemission (HAXPES) to study a delta-doped SrTiO3 layer that consisted of a 3-nm thickness of La-doped SrTiO3 with 6% La embedded in a SrTiO3 film. Results are compared to a thick, uniformily doped La:SrTiO3 layer. We find no indication of a band offset for the delta-doped layer, but evidence of the presence of Ti3+ in both the thick sample and the delta-layer, and indications of a density of states increase near the Fermi energy in the delta-doped layer. These results further demonstrate that HAXPES is a powerful tool for the non-destructive investigation of deeply buried doped layers.