2D material structures have drawn much attention because of the unique characteristics of carriers confined in 2D planes. Various structures have been fabricated for high-performance optoelectronic devices. Herein, via first principles, lateral heterostructures (LHSs) based on antimony (Sb) and bismuth (Bi) are predicted and band structures affected under strain are calculated. For Sb/Bi LHSs, zigzag and armchair atomic configurations are considered. By altering the number of atoms on two sides of the heterostructures, the Sb/Bi LHSs exhibit narrow bandgaps. Moreover, external compressive and tensile strains induce transitions from indirect to direct band structures and further compress the bandgap energy into the midinfrared range. Partial density-of-states analysis indicates that, under the applied strains, the valence band mainly comprises Bi 6p states and Sb 5p states. In addition, charge density distributions indicate that electrons are localized at Bi atoms, whereas holes are localized at Sb atoms, thus exhibiting spatial separation of carriers. A narrow-bandgap material in which the band structure and electronic structure characteristics have great potential for infrared optoelectronic applications is proposed herein.

中文翻译：

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通过第一性原理计算的 Sb/Bi 横向异质结构中的应变相关能带结构和电子特性

二维材料结构由于限制在二维平面内的载流子的独特特性而备受关注。已经为高性能光电器件制造了各种结构。在此，通过第一原理，预测了基于锑 (Sb) 和铋 (Bi) 的横向异质结构 (LHS)，并计算了受应变影响的能带结构。对于 Sb/Bi LHS，考虑了锯齿形和扶手椅原子配置。通过改变异质结构两侧的原子数量，Sb/Bi LHSs 表现出窄带隙。此外，外部压缩和拉伸应变引起从间接带结构到直接带结构的转变，并将带隙能量进一步压缩到中红外范围。偏态密度分析表明，在外加应变下，价带主要包括Bi 6p状态和 Sb 5 p状态。此外，电荷密度分布表明电子位于 Bi 原子处，而空穴位于 Sb 原子处，因此表现出载流子的空间分离。本文提出了一种窄带隙材料，其能带结构和电子结构特性在红外光电应用方面具有巨大潜力。