It has been recently shown that the strain gradient is able to separate the light-excited electron-hole pairs in semiconductors, but how it affects the photoelectric properties of the photo-active materials remains an open question. Here, we demonstrate the critical role of the strain gradient in mediating local photoelectric properties in the strained BiFeO3 thin films by systematically characterizing the local conduction with nanometre lateral resolution in both dark and illuminated conditions. Due to the giant strain gradient manifested at the morphotropic phase boundaries, the associated flexo-photovoltaic effect induces on one side an enhanced photoconduction in the R-phase, and on the other side a negative photoconductivity in the morphotropic -phase. This work offers insight and implication of the strain gradient on the electronic properties in both optoelectronic and photovoltaic devices.
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机译:最近已经显示出应变梯度能够分离半导体中的光激发电子-空穴对,但是它如何影响光敏材料的光电性能仍然是一个悬而未决的问题。在这里,我们通过在黑暗和光照条件下系统地表征具有纳米横向分辨率的局部传导,证明了应变梯度在介导应变BiFeO3薄膜中的局部光电特性中的关键作用。由于在相变相边界处出现了巨大的应变梯度,因此相关的柔光伏效应一方面在R相中引起增强的光电导,另一方面在相变中引起负光电导性。 http://www.w3.org/1998/Math/MathML“ id =” M2“溢出=” scroll“> T mi> ' mo> math>阶段。这项工作提供了应变梯度对光电子和光生伏打器件中电子特性的深入了解和启示。
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