In‐Plane Ferroelectricity in Thin Flakes of Van der Waals Hybrid Perovskite. Issue 51 (17th October 2018)

• Record Type: Journal Article
• Authors: You, Lu; Liu, Fucai; Li, Hongsen; Hu, Yuzhong; Zhou, Shuang; Chang, Lei; Zhou, Yang; Fu, Qundong; Yuan, Guoliang; Dong, Shuai; Fan, Hong Jin; Gruverman, Alexei; Liu, Zheng; Wang, Junling
• Is Part Of: Advanced materials. Volume 30:Issue 51(2018)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2018-10-17
• Subjects: 2D materials -- ferroelectricity -- flexible electromechanical devices -- hybrid perovskite -- piezoresponse force microscopy; Materials -- Periodicals; Chemical vapor deposition -- Periodicals; 620.11
• DOI: 10.1002/adma.201803249
• Languages: English
• ISSNs: 0935-9648

Abstract

Abstract: Collective ferroic orders in van der Waals (vdW) crystals are receiving increasing attention in 2D materials research. The interplay between spatial quantum confinement and long‐range cooperative phenomena not only broadens the horizon of fundamental physics, but also enables new device paradigms and functionalities built upon vdW heterostructures. Here, the in‐plane ferroelectric properties in thin flakes of vdW hybrid perovskite bis(benzylammonium) lead tetrachloride are studied. The ordering of electric dipoles along the layer plane circumvents the depolarization field and preserves the ferroelectricity down to one unit‐cell thickness or two vdW layers at room temperature. The superior performance of the electromechanical energy conversion is demonstrated by exploiting its in‐plane piezoelectricity. The successful isolation of ferroelectric order in atomically thin vdW hybrid perovskite paves the way for nonvolatile flexible electronic devices with the cross‐coupling between strain, charge polarization, and valley degrees of freedom. Abstract : Robust in‐plane ferroelectricity is observed by angular‐resolved piezoelectric force microscopy in a van der Waals lead halide hybrid perovskite. It persists down to one unit‐cell limit at room temperature thanks to the alleviation of the depolarization field effect. This quasi‐2D compound holds great promise for flexible electronic devices due to its strong couplings between strain, polarization, and valley degrees of freedom.