论文标题
晶体氮与黑磷的电子和光学特性：比较第一原理研究
Electronic and optical properties of crystalline nitrogen versus black phosphorus: A comparative first-principles study
论文作者
论文摘要
晶体黑氮（BN）是氮的同类氮，黑磷（BP）结构最近由两个独立的研究组在高压下合成[Ji等人，SCI。 ADV。 6，EABA9206（2020）; Laniel等人，物理。莱特牧师。 124，216001（2020）]。在这里，我们介绍了BN的电子和光学特性的系统研究，该研究的重点是与BP的比较。为此，我们在电子和光学通道中使用顶点校正的最先进的Quasiparticle $ GW $方法。尽管有许多相似之处，但仍发现BN的性质有很大差异。与BP不同，BN表现出较大的光学间隙（2.5 vs 0.26 eV），使BN在可见光谱区域具有高度各向异性的光学响应。这种差异主要归因于BN中的介电筛选大大降低，从而增强了有效的库仑相互作用。尽管相对较强的库仑相互作用，但两种材料中的激子形成在很大程度上受到了抑制。我们对弹性特性的分析表明，BN的刚度与钻石相当。
Crystalline black nitrogen (BN) is an allotrope of nitrogen with the black phosphorus (BP) structure recently synthesized at high pressure by two independent research groups [Ji et al., Sci. Adv. 6, eaba9206 (2020); Laniel et al., Phys. Rev. Lett. 124, 216001 (2020)]. Here, we present a systematic study of the electronic and optical properties of BN focusing on its comparison with BP. To this end, we use the state-of-the-art quasiparticle self-consistent $GW$ approach with vertex corrections in both the electronic and optical channels. Despite many similarities, the properties of BN are found to be considerably different. Unlike BP, BN exhibits a larger optical gap (2.5 vs 0.26 eV), making BN transparent in the visible spectral region with a highly anisotropic optical response. This difference can be primarily attributed to a considerably reduced dielectric screening in BN, leading to enhancement of the effective Coulomb interaction. Despite relatively strong Coulomb interaction, exciton formation is largely suppressed in both materials. Our analysis of the elastic properties shows exceptionally high stiffness of BN, comparable to that of diamond.
