The layer-dependent optoelectronic properties of monolayer, bilayer and trilayer black phosphorus (BP) are studied by using the first-principles calculations based on density functional theory (DFT). The valence band splits and the density of states (DOS) in the conduction band obviously shift to the Fermi surface with the increased layer number. The atomic p orbital of BP plays an decisive role in determining the electronic and optical properties, which are drastically different from those of graphene and transition metal dichalogenides (TMDs). The increase of the layer number leads to the metal characteristics. The extinction coefficient and photoconductivity show strong optical responses to the ultraviolet (UV) light, which further increase with the number of layers. BP layers can reflect UV rays effectively because of their metallic properties in the UV energy range. Our study shows that the interlayer interaction can intensely change the electronic and optical properties of BP.

中文翻译：

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黑磷的层依赖光电特性

利用基于密度泛函理论（DFT）的第一性原理计算研究了单层、双层和三层黑磷（BP）的层相关光电特性。随着层数的增加，价带分裂，导带中的态密度（DOS）明显向费米面移动。BP的原子p轨道在决定电子和光学性质方面起着决定性的作用，这与石墨烯和过渡金属二卤化物（TMDs）截然不同。层数的增加导致金属特性。消光系数和光电导率对紫外 (UV) 光表现出强烈的光学响应，随着层数的增加而进一步增加。BP 层可以有效地反射紫外线，因为它们在紫外线能量范围内具有金属特性。我们的研究表明，层间相互作用可以强烈改变 BP 的电子和光学性质。