TY - JOUR
T1 - Efficient photovoltaic current generation at ferroelectric domain walls
JF - Physical Review Letters
Y1 - 2011/
A1 - J. Seidel
A1 - D. Fu
A1 - S.-Y. Yang
A1 - E. Alarcón-Lladó
A1 - J. Wu
A1 - Ramamoorthy Ramesh
A1 - J.W. Ager
KW - Band gaps
KW - Charged carriers
KW - Diffusion currents
KW - Domain walls
KW - Electrons and holes
KW - Electrostatic potentials
KW - Ferroelectric domains
KW - Ferroelectric materials
KW - ferroelectricity
KW - Internal quantum efficiency
KW - Nano scale
KW - Open circuits
KW - Ordered domains
KW - Periodic domain structures
KW - Periodic potentials
KW - Periodic structures
KW - Photovoltages
KW - Photovoltaic currents
KW - Photovoltaic effects
KW - Recombination rate
AB - We elucidate the mechanism of a newly observed photovoltaic effect which occurs in ferroelectrics with periodic domain structures. Under sufficiently strong illumination, domain walls function as nanoscale generators of the photovoltaic current. The steps in the electrostatic potential function to accumulate electrons and holes on opposite sides of the walls while locally reducing the concentration of the oppositely charged carriers. As a result, the recombination rate adjacent to the walls is reduced, leading to a net diffusion current. In open circuit, photovoltages for periodically ordered domain walls are additive and voltages much larger than the band gap can be generated. The internal quantum efficiency for individual domain walls can be surprisingly high, approaching 10% for above band-gap photons. Although we have found the effect in BiFeO3 films, it should occur in any system with a similar periodic potential. © 2011 American Physical Society.
VL - 107
N1 - cited By 259
ER -