Understanding the nature of remnant polarization enhancement, coercive voltage offset and time-dependent photocurrent in ferroelectric films irradiated by ultraviolet light
Understanding the nature of remnant polarization enhancement, coercive voltage offset and time-dependent photocurrent in ferroelectric films irradiated by ultraviolet light
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DOI：
10.1039/c2jm32102e
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发表时间：
2012-06
影响因子：
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通讯作者：
Dawei Cao;Chunyan Wang;F. Zheng;Liang Fang;Wen Dong;M. Shen
中科院分区：
文献类型：
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作者：
Dawei Cao;Chunyan Wang;F. Zheng;Liang Fang;Wen Dong;M. Shen
人们普遍认为，紫外光照射铁电薄膜会导致光生载流子在畴壁和/或电极-薄膜界面上的积累，从而导致可逆剩余极化的降低，从而产生极化印记。然而，在本文中，在Pb（Zr 0.2Ti 0.8）O3（PZT）薄膜显示出增强的剩余极化时，紫外光照射。随时间变化的光电流和磁滞回线的PZT薄膜的光电流和矫顽电压偏移的瞬态行为密切相关的极化状态，可移动的缺陷电荷（主要是氧空位）的密度，老化时间。基于压电响应力显微镜的观察，提出了所观察到的光电和铁电现象背后的机制。
It is widely accepted that ultraviolet (UV) light illumination of ferroelectric films can result in polarization imprint because of the accumulation of photoinduced carriers on the domain walls and/or on the electrode–film interfaces, and then the decrease of the reversible remnant polarization. In this paper, however, the enhancement of remnant polarization was exhibited in Pb(Zr0.2Ti0.8)O3 (PZT) films when irradiated by UV light. The time-dependent photocurrent and hysteresis loop of PZT films indicated that the transient behavior of photocurrent and coercive voltage offset were closely related to the polarization states, moveable defect charge (mainly oxygen vacancy) density, and aging time. Based on the observation of piezoresponse force microscopy, the mechanism behind the observed photoelectric and ferroelectric phenomena was proposed.