“…To further study the interface, the BE spectra of Ti 2p, O 1s, and Si 2p signals at the interface were analyzed and are shown in Figures 2b-d, respectively. After deconvolution, the Ti 2p 2p3/2 spectra have three peaks, which are associated with TiO (454.7 eV), Ti2O3 (457 eV), and TiO2 (458.7 eV) [22], indicating that oxygen is deficient in the TiO2 film. The O1s spectra also have three peaks, which are associated with TiO2 (530.3 eV), oxygendeficient TiO2 (531.1 eV), and SiO2 (532.2 eV) [22,23].…”