A penta-BCP sheet with strong piezoelectricity and a record high positive Poisson's ratio. Issue 28 (7th July 2022)

• Record Type: Journal Article
• Authors: Hou, Changsheng; Shen, Yiheng; Sun, Wei; Chen, Yanyan; Ni, Dongyuan; Wang, Qian
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 28(2022)
• Page Start: 10302
• Page End: 10309
• Publication Date: 2022-07-07
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d2tc02053j
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : The penta-BCP sheet is the first pentagon-based sheet with a Poisson's ratio larger than 1.00, with a record high value of 1.30 along the [010] direction, possessing strong piezoelectricity due to its unique geometry and polarized bonding. Abstract : Two-dimensional structures composed solely of pentagonal motifs are of particular interest due to their unique geometries and novel properties. In particular, the broken centrosymmetry in many pentagon-based sheets results in piezoelectricity. Herein, we rationally design a penta-BCP sheet with large intrinsic polarization and weak mechanical strength. First-principles calculations reveal that the penta-BCP sheet is a dynamically, thermally, and mechanically stable semiconductor with an indirect band gap of 2.97 eV. More interestingly, the penta-BCP sheet is found to be the first penta-sheet with a positive Poisson's ratio larger than 1.00 (1.30), and possesses prominent spontaneous polarization ( P s = 4.66 × 10 −10 C m −1 ) and piezoelectricity ( d 21 = −13.57 pm V −1, and d 22 = 6.33 pm V −1 ). The large positive Poisson's ratio coupled with its piezoelectricity leads to a significant overall piezoelectric response of 24 pm V −1 . This study expands the family of ternary pentagon-based sheets with outstanding properties.