Self-polarized Poly(vinylidene fluoride) Ultrathin Film and Its Piezo/Ferroelectric Properties.
Self-polarized Poly(vinylidene fluoride) Ultrathin Film and Its Piezo/Ferroelectric Properties.
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DOI：
10.1021/acsami.0c06809
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发表时间：
2020-06
影响因子：
9.5
通讯作者：
Junming Liu;Qiang Zhao;Yufei Dong;Xiaoli Sun;Zhijun Hu;Huanli Dong;Wenping Hu;Shouke Yan
中科院分区：
文献类型：
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作者：
Junming Liu;Qiang Zhao;Yufei Dong;Xiaoli Sun;Zhijun Hu;Huanli Dong;Wenping Hu;Shouke Yan
具有超低功耗的有机非易失性存储器是下一代存储器应用的关键研究需求。然而，获得具有低漏电流和稳定铁电开关的大面积高取向铁电超薄膜仍然是实现铁电存储晶体管低工作电压的挑战。在此，通过熔体拉伸技术制备了具有高取向度的理想铁电纯PVDF超薄膜，无需后热处理和辅助稳定过程。 PVDF 超薄膜是自极化的，偶极矩主要垂直方向，表现出 25 pm V-1 的 d33 和通过压电响应力显微镜 (PFM) 表征的约 3 V 的超低矫顽电压。基于具有由六层熔拉薄膜形成的有源层的PVDF电容器，确定了6.3 μC cm-2的剩余极化（Pr）。采用单层熔拉PVDF超薄膜作为绝缘层，制造出底栅顶接触铁电场效应晶体管（FeFET），工作电压为5 V。在零栅极偏压和阈值电压漂移约为2 V的情况下，其开/关电流比为1000的存储窗口。
Organic nonvolatile memory with ultralow power consumption is a critical research demand for next-generation memory applications. However, obtaining large area highly oriented ferroelectric ultrathin film with low leakage current and stable ferroelectric switching remains a challenge for achieving low operation voltage in ferroelectric memory transistors. Here, an ideal ferroelectric neat PVDF ultrathin film with high degree of orientation is fabricated by a melt-draw technique without post thermal treatment and assisted stabilization process. The PVDF ultrathin film is self-polarized with predominantly vertical orientation of dipole moments, exhibiting a d33 of 25 pm V-1 and the ultralow coercive voltage of approximately 3 V characterized by piezoresponse force microscopy (PFM). The remnant polarization (Pr) of 6.3 μC cm-2 is identified based on PVDF capacitor with active layer formed by six layers of the melt-drawn thin films. By employing a single layer melt-drawn PVDF ultrathin film as an insulation layer, a bottom-gate-top-contact ferroelectric field-effect transistor (FeFET) is fabricated with the very low operation voltage of 5 V. It exhibits a memory window with on/off current ratio of 1000 at zero gate bias and threshold voltage shift of around 2 V.