Nanoscale Bandgap Tuning across an Inhomogeneous Ferroelectric Interface

Jing Wang; Houbing Huang; Wangqiang He; Qinghua Zhang; Danni Yang; Yuelin Zhang; Renrong Liang; Chuanshou Wang; Xingqiao Ma; Lin Gu; Longqing Chen; Ce-Wen Nan; Jinxing Zhang

doi:10.1021/acsami.7b05138

arXiv · 1709.08788

Nanoscale Bandgap Tuning across an Inhomogeneous Ferroelectric Interface

Jing Wang·Houbing Huang·Wangqiang He·Qinghua Zhang·Danni Yang·Yuelin Zhang·Renrong Liang·Chuanshou Wang·Xingqiao Ma·Lin Gu·Longqing Chen·Ce-Wen Nan·Jinxing Zhang

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Abstract

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 photovolatic effects and the spectral response of the photocurrent were explore to illustrate the reversible bandgap variation (~0.3eV). This local-strain-engineered bandgap has been further revealed by in situ 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 opticallyrelated behaviors (photovoltaic, photoemission, and photocatalyst effects) affected by order parameters such as charge, orbital, and lattice parameters.

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Jing Wang, Houbing Huang, Wangqiang He, Qinghua Zhang, Danni Yang, Yuelin Zhang, Renrong Liang, Chuanshou Wang, Xingqiao Ma, Lin Gu, Longqing Chen, Ce-Wen Nan, Jinxing Zhang. 2017-09-26. Nanoscale Bandgap Tuning across an Inhomogeneous Ferroelectric Interface. https://doi.org/10.1021/acsami.7b05138

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