The bulk photovoltaic effect (BPVE) offers an interesting approach to generate a steady photocurrent in a single-phase material under homogeneous illumination, and it has been extensively investigated in ferroelectrics exhibiting spontaneous polarization that breaks inversion symmetry. Flexoelectricity breaks inversion symmetry via a strain gradient in the otherwise nonpolar materials, enabling manipulation of ferroelectric order without an electric field. Combining these two effects, we demonstrate active mechanical control of BPVE in suspended 2-dimensional CuInP₂S₆ (CIPS) that is ferroelectric yet sensitive to electric field, which enables practical photodetection with an order of magnitude enhancement in performance. The suspended CIPS exhibits a 20-fold increase in photocurrent, which can be continuously modulated by either mechanical force or light polarization. The flexoelectrically engineered photodetection device, activated by air pressure and without any optimization, possesses a responsivity of 2.45 × 10^–2 A/W and a detectivity of 1.73 × 10¹¹ jones, which are superior to those of ferroelectric-based photodetection and comparable to those of the commercial Si photodiode.

中文翻译：

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体光伏光电探测器的柔性电工程


体光伏效应（BPVE）提供了一种有趣的方法，可以在均匀照明下在单相材料中产生稳定的光电流，并且它已在表现出破坏反演对称性的自发极化的铁电体中得到广泛研究。挠曲电通过非极性材料中的应变梯度打破反演对称性，从而无需电场即可操纵铁电序。结合这两种效应，我们证明了悬浮二维 CuInP ₂ S ₆ (CIPS) 中 BPVE 的主动机械控制，它是铁电但对电场敏感，这使得实际的光电检测成为可能性能提高一个数量级。悬浮的 CIPS 的光电流增加了 20 倍，可以通过机械力或光偏振连续调制。柔性电工程光电探测装置由气压激活且未经任何优化，具有 2.45 × 10 ^–2 A/W 的响应度和 1.73 × 10 ¹¹ jones 的探测率，优于基于铁电的光电检测，并且与商用硅光电二极管相当。