Zheng Congqin, Li Xin, Li Wei, Chen Tiantian, Lv Fu, Huang Yuhui, Li Qian, Wu Yongjun, Hong Zijian
School of Materials Science and Engineering, Zhejiang University, Hangzhou, China.
School of Materials Science and Engineering, Tsinghua University, Beijing, China.
Nat Commun. 2024 Sep 5;15(1):7767. doi: 10.1038/s41467-024-52207-7.
Molecular ferroelectrics have garnered significant attention due to their structural tunability, low synthesis temperature, and high flexibility. Herein, we successfully synthesized imidazole perchlorate (ImClO) single crystals and high-quality, highly-oriented thin films on Si substrates. These films demonstrated a high inverse piezoelectric coefficient of 55.7 pm/V. Two types of domain bands were observed: type-I bands tilted ~60 relative to the horizontal axis, and type-II bands positioned perpendicular to the horizontal axis. Under a + 20 V bias, type-I bands showed a reduction and detachment of 180 domain walls to form a needle-like domain. It extended toward the band boundary after applying -20 V bias, which grew along the boundary upon contact. In contrast, type-II bands showed straight domain wall motion and displayed a higher piezoresponse than type-I bands. The growth of high quality molecular ferroelectric thin films on Si substrates paves the way for the development of on-chip devices.
分子铁电体因其结构可调性、低合成温度和高柔韧性而备受关注。在此，我们成功地在硅衬底上合成了高氯酸咪唑（ImClO）单晶以及高质量、高度取向的薄膜。这些薄膜表现出55.7 pm/V的高逆压电系数。观察到两种类型的畴带：I型带相对于水平轴倾斜约60°，II型带垂直于水平轴定位。在+20 V偏压下，I型带显示180°畴壁的减少和分离，形成针状畴。施加-20 V偏压后，它向带边界延伸，接触时沿边界生长。相比之下，II型带显示出直的畴壁运动，并且比I型带表现出更高的压电响应。在硅衬底上生长高质量分子铁电薄膜为片上器件的发展铺平了道路。
