Bilayer Phosphorene: Effect of Stacking Order on Bandgap and Its Potential Applications in Thin-Film Solar Cells
Bilayer Phosphorene: Effect of Stacking Order on Bandgap and Its Potential Applications in Thin-Film Solar Cells
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DOI：
10.1021/jz500409m
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发表时间：
2014-04-03
影响因子：
5.7
通讯作者：
Zeng, Xiao Cheng
中科院分区：
文献类型：
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作者：
Dai, Jun;Zeng, Xiao Cheng
磷烯是一种单层黑磷，不仅是因为它是一种天然的p型半导体，而且还因为它具有与层数有关的直接带隙(在0.3-1.5 eV的范围内)，因此在纳米电子领域具有很好的应用前景。在密度泛函理论计算的基础上，我们研究了具有不同堆积顺序的双层磷烯的电子性质。我们发现，对于三种不同的堆积顺序，双层膜的直接禁带宽度可以从0.78 eV到1.04 eV变化。另外，垂直电场还可以使带隙进一步减小到0.56 eV(场强为0.5V/埃)。更重要的是，我们发现当MoS_2的单层与p型AA或AB堆积的双层磷烯叠加时，组合的三层膜可以成为一种有效的具有II型异质结取向的太阳能电池材料。据预测，AA或AB堆叠的双层磷烯的功率转换效率将类似于18%或16%，高于最先进的三层石墨烯/过渡金属二卤化物太阳能电池的报道效率。
Phosphorene, a monolayer of black phosphorus, is promising for nanoelectronic applications not only because it is a natural p-type semiconductor but also because it possesses a layer-number-dependent direct bandgap (in the range of 0.3 to 1.5 eV). On basis of the density functional theory calculations, we investigate electronic properties of the bilayer phosphorene with different stacking orders. We find that the direct bandgap of the bilayers can vary from 0.78 to 1.04 eV with three different stacking orders. In addition, a vertical electric field can further reduce the bandgap to 0.56 eV (at the field strength 0.5 V/angstrom). More importantly, we find that when a monolayer of MoS2 is superimposed with the p-type AA- or AB-stacked bilayer phosphorene, the combined trilayer can be an effective solar-cell material with type-II heterojunction alignment. The power conversion efficiency is predicted to be similar to 18 or 16% with AA- or AB-stacked bilayer phosphorene, higher than reported efficiencies of the state-of-the-art trilayer graphene/transition metal dichalcogenide solar cells.