Ultrafast Photovoltaic Response in Ferroelectric Nanolayers

作者：Daranciang Dan^*; Highland Matthew J; Wen Haidan; Young Steve M; Brandt Nathaniel C; Hwang Harold Y; Vattilana Michael; Nicoul Matthieu; Quirin Florian; Goodfellow John; Qi Tingting; Grinberg Ilya; Fritz David M; Cammarata Marco; Zhu Diling; Lemke Henrik T; Walko Donald A; Dufresne Eric M; Li Yuelin; Larsson Jorgen; Reis David A; Sokolowski Tinten Klaus; Nelson Keith A; Rappe Andrew M; Fuoss Paul H; Stephenson G Brian; Lindenberg Aaron M

来源：Physical Review Letters, 2012, 108(8): 087601.

DOI：10.1103/PhysRevLett.108.087601

We show that light drives large-amplitude structural changes in thin films of the prototypical ferroelectric PbTiO3 via direct coupling to its intrinsic photovoltaic response. Using time-resolved x-ray scattering to visualize atomic displacements on femtosecond time scales, photoinduced changes in the unit-cell tetragonality are observed. These are driven by the motion of photogenerated free charges within the ferroelectric and can be simply explained by a model including both shift and screening currents, associated with the displacement of electrons first antiparallel to and then parallel to the ferroelectric polarization direction.

• 出版日期2012-2-23