Angle-resolved photoemission study of Nb-dopedSrTiO3

Structure and correlation effects in semiconductingSrTiO3

“…3͒ suggest that the electron-phonon coupling might play an important role for the thermoelectricity in doped STO. While the conduction-band structure of the n-doped STO was previously extracted using the photoemission spectroscopy [19][20][21][22] as well as the magnetotransport, 17,18 the precise evaluation of the Fermi-surface shape, effective mass, and electron-phonon interaction from ARPES bandstructure measurements is unique to the present study. The present work is only possible because of the very high energy and momentum resolution of the experiments that also cover several Brillouin zones of STO.…”

“…23 To introduce negative carriers into the samples, we annealed them in ultrahigh vacuum ͑Ͻ1 ϫ 10 −9 Torr͒ at ϳ1000°C for 30 min, upon which oxygen vacancies are introduced with electron donation. 20 We are then able to examine the conduction-band minimum structure over an energy range of ϳ50 meV. The carrier concentration was estimated to be n ϳ 10 20 cm −3 from the size of Fermi-surface area ͑see below͒.…”

Final-state effect on x-ray photoelectron spectrum of nominallyd1andn-dopedd0transition-metal oxides

“…n core = 0), all TM d levels are shifted down by U dc to screen the core hole. By fitting to published experimental data from XPS of SrTiO 3 , ellipsometry, and angle-resolved photoemission spectroscopy (ARPES) [15,32,[41][42][43], we take ǫ d (e g ) = 2.0 eV, ǫ d (t 2g ) = 0 eV, ǫ p (Γ) = −3.0 eV, V (e g ) = 2.5eV, V (t 2g ) = −1.3 eV, U = 6.0 eV, and U dc = 8.0 eV [44]. This problem can be solved exactly by the technique introduced by Gunnarsson and Schönhammer [12,45], and the details are provided in Appendix B.…”

Tuning the electronic effective mass in double-dopedSrTiO3

“…Effective mass values have been conventionally evaluated using cyclotron resonance, 20 reflectivity, 21 photoemission, 22 and Shubnikov-de Haas effect 23 for various single crystals of semiconductors. The other common method is using transport data to calculate the density of states effective mass.…”