1 research outputs found
Nanoscale Bandgap Tuning across an Inhomogeneous Ferroelectric Interface
We report nanoscale
bandgap engineering via a local strain across the inhomogeneous ferroelectric
interface, which is controlled by the visible-light-excited probe
voltage. Switchable photovoltaic effects and the spectral response
of the photocurrent were explored to illustrate the reversible bandgap
variation (∼0.3 eV). This local-strain-engineered bandgap has
been further revealed by <i>in situ</i> probe-voltage-assisted
valence electron energy-loss spectroscopy (EELS). Phase-field simulations
and first-principle calculations were also employed for illustration
of the large local strain and the bandgap variation in ferroelectric
perovskite oxides. This reversible bandgap tuning in complex oxides
demonstrates a framework for the understanding of the optically related
behaviors (photovoltaic, photoemission, and photocatalyst effects)
affected by order parameters such as charge, orbital, and lattice
parameters