Figure 5 : Spatial confinement of the 2DEG at the γ-Al2O3/STO heterointerface determined by angle-resolved XPS.

From: A high-mobility two-dimensional electron gas at the spinel/perovskite interface of γ-Al2O3/SrTiO3

Figure 5

(a) The Ti 2p3/2 XPS spectra at various emission angles φ for the d=2.5 uc sample. (b) The angle dependence of the ratio of Ti3+ to Ti4+ signal, I(Ti3+)/I(Ti4+), indicates a strong confinement of the conduction layer within 0.9 nm. Error bars indicate deviations, ±10%, of experimental values.