自支撑锆钛酸铅薄膜制备及性能表征

柔性压电器件在能量收集、医疗及传感等领域有广泛的应用前景，但传统无机压电材料不具备柔性，而柔性聚合物的压电性能与刚性的无机材料相比又有较大差距。利用脉冲激光沉积技术制备水溶性 Sr₃Al₂O₆（SAO）薄膜这一工艺的发展，为制备柔性自支撑无机压电薄膜提供了可能性。本文利用脉冲激光沉积技术，利用水溶性 SAO 牺牲层，成功制备高质量柔性自支撑锆钛酸铅 (PZT) 薄膜，并首次测量了其力电耦合性能，取得创新成果如下：
1）系统研究了基于水溶性 SAO 牺牲层的自支撑 PZT 薄膜脉冲激光沉积生长工艺，以SrTiO₃(STO) 作为衬底，确认了SAO 的最佳生长参数为：衬底温度705℃，氧气分压100mTorr，激光能量密度 1.3 J ⋅ cm−2；PZT 薄膜生长的最优条件为：衬底温度 600℃，激光能量密度 1.3 J ⋅ cm−2，氧气分压 200mTorr。基于以上参数进一步实现基于STO 衬底的SAO/PZT 双层薄膜的生长。通过XRD 确定了薄膜的物相，通过原子力显微镜确定了高质量的层状生长模式。
2）探索了两种不同的自支撑薄膜转移工艺，在将 SAO 牺牲层水溶后，利用二维转移台和热释放胶带实现了完整、低污染和毫米级别的自支撑PZT 薄膜转移，在微加工坑洞硅衬底上得到部分悬空的自支撑 PZT 薄膜。
3）基于悬空的自支撑PZT 薄膜，利用原子力显微镜得到其受力-形变曲线，进而得到其杨氏模量。通过统计，发现悬空自支撑PZT 薄膜的杨氏模量为162 ±20GPa，比同组分的 PZT 块体有较大提高。
4）通过双频追踪与时序激励法两种方法，利用原子力显微镜压电力显微模式测量了支撑与悬空部分PZT 薄膜的压电性能。结果表明，PZT 薄膜悬空区域的谐振频率相比衬底支撑区域有较大差异，在压电响应上也从 15-20pm 提升至 20-25pm。
本研究探索了自支撑PZT 生长及转移工艺，并测量了其杨氏模量和压电性能，为基于自支撑 PZT 薄膜的柔性压电器件设计与制备奠定了基础。

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