Two-Dimensional Hybrid Perovskite-Type Ferroelectric for Highly Polarization-Sensitive Shortwave Photodetection

作者：Lina Li, Xitao Liu, Yaobin Li, Zhiyun Xu, Zhenyue Wu, Shiguo Han, Kewen Tao, Maochun Hong, Junhua Luo, Zhihua Sun · 发表于：Journal of the American Chemical Society · 年份：2019 · DOI：10.1021/jacs.8b12948 · 被引用次数：335 · 研究领域：Perovskite Materials and Applications、2D Materials and Applications、Solid-state spectroscopy and crystallography

Two-dimensional (2D) materials have been well developed for polarization-sensitive photodetection, while new 2D members used in shortwave region (>2.5 eV) still remain scarce. The family of 2D hybrid perovskite ferroelectrics, in which the coupling of spontaneous polarization ( P s ) and light benefits dissociation of photoinduced carriers, has shown great potential in this portfolio. Here, we report a new 2D hybrid perovskite ferroelectric, [CH 3 (CH 2 ) 3 NH 3 ] 2 (CH 3 NH 3 )Pb 2 Br 7 ( 1 ), which exhibits a superior P s of 3.6 μC/cm 2 and a relatively wide bandgap (∼2.55 eV). The unique 2D perovskite motif results in an intrinsic anisotropy of optical absorption (the ratio α c /α a ≈ 1.9 at 405 nm), involving its polarization-sensitive activity. As expected, the strongest photoresponses were observed along the c -axis (i.e., parallel to P s ), along with a large dichroism ratio ( I ph c / I ph a ≈ 2.0) and highly sensitive detectivity up to ∼10 9 Jones. Further, crystal-device of 1 shows a fast responding rate (∼20 μs) and excellent antifatigued merits. As pioneering work, 1 is the first polarization-sensitive ferroelectric in the new branch of 2D hybrid perovskites. Such intriguing behaviors make 1 a potential candidate for the shortwave polarized-light detection, which also sheds light on new functionalities for future optoelectronic application of hybrid perovskites.