Build Borophite from Borophenes: A Boron Analogue Graphite.

Wang, Meng-Hui; Yi, Wen-Cai; Song, Hao-Lin; Wu, Fa-Zhi; Fu, Yu-Hao; Liu, Xiao-Bing; Cui, Zhong-Hua · Nano Lett · 2024

basic_science · Level V

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Abstract

Unlike graphene derived from graphite, borophenes represent a distinct class of synthetic two-dimensional materials devoid of analogous bulk-layered allotropes, leading to covalent bonding within borophenes instead of van der Waals (vdW) stacking. Our investigation focuses on 665 vdW-stacking boron bilayers to uncover potential bulk-layered boron allotropes through vdW stacking. Systematic high-throughput screening and stability analysis reveal a prevailing inclination toward covalently bonded layers in the majority of boron bilayers. However, an intriguing outlier emerges in δ<sub>5</sub> borophene, demonstrating potential as a vdW-stacking candidate. We delve into electronic and topological structural similarities between δ<sub>5</sub> borophene and graphene, shedding light on the structural integrity and stability of vdW-stacked boron structures across bilayers, multilayers, and bulk-layered allotropes. The δ<sub>5</sub> borophene analogues exhibit metallic properties and characteristics of phonon-mediated superconductors, boasting a critical temperature near 22 K. This study paves the way for the concept of "borophite", a long-awaited boron analogue of graphite.