Screening transition metal-based polar pentagonal monolayers with large piezoelectricity and shift current
Screening transition metal-based polar pentagonal monolayers with large piezoelectricity and shift current
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DOI：
10.1038/s41524-022-00728-4
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发表时间：
2022-03-15
影响因子：
9.7
通讯作者：
Wang, Qian
中科院分区：
文献类型：
--
作者：
Guo, Yaguang;Zhou, Jian;Wang, Qian
完全由五角形图案组成的二维材料因其广泛的应用而引起人们的兴趣。在这里，我们证明了平面内的极对称性可以存在于三元五方膜中，其中的诱导极化与铁电相变、应变梯度和层的堆积等特定条件无关，而是一种来自有序排列的极性键的本征结构性质。基于高通量筛选方法和第一性原理计算，我们发现了八种稳定的二维极性过渡金属化合物，它们具有许多有趣的性质。特别是，它们的压电系数比二维元素结构和二元五方结构大三个数量级，体光电压漂移电流可达300mA·V-2，优于传统的二维铁电材料如GeS。我们确定的五角单分子膜不仅扩大了2D热释电材料的家族，而且具有能量转换的潜力。
Two-dimensional (2D) materials entirely composed of pentagon motifs are of interest for their wide applications. Here, we demonstrate that in-plane polar symmetry can exist in ternary pentagonal monolayers, where the induced electric polarization is not associated with specific conditions, such as ferroelectric phase transition, strain gradient, and layer stacking, but is an intrinsic structural property coming from the orderly arranged polar bonds. Based on the high-throughput screening method and first-principles calculations, we find eight stable 2D polar transition metal compounds with a number of intriguing properties. In particular, their piezoelectric coefficients are three orders of magnitude larger than those of 2D elemental and binary pentagonal structures, and their bulk photovaltaic shift current can reach up to 300 mu A V-2, superior to that of 2D conventional ferroelectric materials such as GeS. Our identified pentagonal monolayers not only expand the family of 2D pyroelectric materials, but also hold potential for energy conversions.