Electronic surface properties of SrTiO3 derived from a surface photovoltage study

摘要: In the past, surface photovoltage (SPV) analysis has been successfully applied to derive electronic defect status of a number wide-bandgap semiconductor surfaces. Here, method is model perovskite strontium titanate, whose SPV phenomena are comprehensively studied over seven decades excitation-light intensity. The was recorded by Kelvin probe setup as function wavelength in order extract energetic positions states within bandgap. At selected wavelengths addressing distinct states, transients were measured light intensity and temperature. Several models known from literature used estimate cross check state parameters such densities, capture sections for photons electrons, band bending dark under illumination. contrast other materials, SrTiO3 exhibit highly complex shapes, i.e. they (i) show signatures multiple carrier transitions, (ii) mixtures bulk contributions, well (iii) both ex- intrinsic processes.