论文标题
MOSI2N4中高度可调和强绑定的激子通过应变工程
Highly Tunable and Strong Bound Exciton in MoSi2N4 via Strain Engineering
论文作者
论文摘要
由最近合成的分层材料MOSI2N4激励，我们使用G0W0和Bethe-Salpeter方程（BSE）计算研究了单层MOSI2N4准粒子的激子响应。 MOSI2N4由封闭的2H-MOS2的中央MON2层类似物组成，该结构由2H-MOS2的中央MON2层类似物组成，MOSI2N4具有限制在Central Mon2层的边缘轨道，该轨道在K-Point的中央MON2层上具有相似的Sub-Valley，为2H-MOS2。由于旋转轨道耦合（SOC），山谷拆分（〜130 MeV）在频谱中产生了双倍线。 MOSI2N4中的激子显示出强大的结合能高达0.95 eV，光带隙为2.44 eV。电子间隙和光学间隙都对拉伸菌株高度敏感，并变成红移，尽管激子结合能的边缘变化。通过保护封顶的罪行，量子在MOSI2N4中限制了激子，而无需像BN这样的其他钝化层，将为强劲的发射提供明亮的新平台，并从环境中进行部分筛选的干扰。
Motivated by the recently synthesized layered material MoSi2N4, we investigated excitonic response of quasiparticle of monolayer MoSi2N4 by using G0W0 and Bethe-Salpeter equation (BSE) calculations. With a dually sandwiched structure consisting of a central MoN2 layer analogue of 2H-MoS2 capped with silicon-nitrogen (SiN) honeycomb outer layers, MoSi2N4 possesses frontier orbitals confined at the central MoN2 layer with similar sub-valley at K-point as 2H-MoS2. The valley splitting (~130 meV) due to the spin-orbital coupling (SOC) gives rise to a doublet in the spectrum. Excitons in MoSi2N4 shows a strong binding energy up to 0.95 eV with the optical bandgap of 2.44 eV. Both electronic and optical gaps are highly sensitive to tensile strains and become redshift albeit a marginal change of exciton binding energy. With the protection of capped SiN layers, quantum confined excitons in MoSi2N4 without the need of additional passivation layer like BN would provide a bright new platform for robust emission with partially screened disturbance from environment.
