Surface electron-phonon interaction of the nanocrystalline semiconductors

The combination of the surface photovoltaic and the photoacoustic techniques was used for probing the surface electron-phonon interaction (SEPI) and the mechanism of nonradiative transitions of the three typical nanocrystalline semiconductors at room temperature upon illumination of UV. near IR light. The results showed that the SEPIs on the La-doped nano-TiO 2 and the nano-La 1-x Sr x FeO 3 had nothing to do with the charge transfer transitions of the main bandgap. The SEPI of the nano-La 1-x Sr x FeO 3 depended close on both exciton transitions and crystal-field transitions upon illumination at the photon energy hnu was smaller than the bandgap E g, La 1-x Sr x FeO 3 . The photogenic free charge carriers at hnu