We investigate the photogalvanic effect in nitrogen-doped monolayer molybdenum disulfide (MoS2) under the perpendicular irradiation, using first-principles calculations combined with non-equilibrium Green function formalism. We provide a detailed analysis on the behavior of photoresponse based on the band structure and in particular the joint density of states. We thereby identify different mechanisms leading to the existence of zero points, where the photocurrent vanishes. In particular, while the zero point in the linear photovoltaic effect is due to forbidden transition, their appearance in the circular photovoltaic effect results from the identical intensity splitting of the valance band and the conduction band in the presence of Rashba and Dresslhaus spin-orbit coupling. Furthermore, our results reveal a strong circular photogalvanic effect of nitrogen-doped monolayer MoS2, which is two orders of magnitude larger than that induced by the linearly polarized light.

中文翻译：

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从第一原理看，掺氮单层MoS2中的光电流效应。

我们使用第一性原理计算与非平衡Green函数形式相结合，研究了垂直照射下掺氮单层二硫化钼（MoS2）中的光电流效应。我们基于能带结构，尤其是状态的联合密度，对光响应的行为进行了详细的分析。因此，我们确定了导致光电流消失的零点的不同机制。特别是，虽然线性光伏效应中的零点是由于禁止的跃迁而引起的，但它们在圆形光伏效应中的出现是由于在存在Rashba和Dresslhaus自旋轨道耦合的情况下，价带和导带的强度分裂相同。此外，