Using the first principles calculations, we analyze the structural and electronic properties of a ${\mathrm{PtSe}}_2$ monolayer on Pt substrate, obtained by direct selenization of the Pt(111) surface [Wang et al., Nano Lett. 15, 4013 (2015)]. We demonstrate that in order to reproduce the experimental result that ${\mathrm{PtSe}}_2$ is physisorbed on the surface, the surface must be passivated. We propose that this passivation is most likely due to intercalation of Se atoms between ${\mathrm{PtSe}}_2$ and Pt surface during the selenization process. In this case the mean distance between the Se-passivated surface and ${\mathrm{PtSe}}_2$ is found to be $3.24\text{Å}$, which is consistent with the distance that can be extracted from the scanning transmission electron microscopy image of the hybrid system, and the adsorption energy is found to fall into physisorption range. Therefore, our findings provide an insight into the synthesis of ${\mathrm{PtSe}}_2$ by direct selenization: A realistic structural model should include a Se-passivated surface and not a clean one.

中文翻译：

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通过直接硒化PtSe2合成PtSe2期间PtSe2与Pt表面之间的Se嵌入（111）

使用第一原理计算，我们分析了结构的 ${\mathrm{铂硒}}_2$通过直接硒化Pt（111）表面获得的Pt衬底上的单层[Wang等。，Nano Lett。 15，4013（2015）]。我们证明为了重现实验结果，${\mathrm{铂硒}}_2$被物理吸附在表面上时，表面必须被钝化。我们认为这种钝化很可能是由于硒原子之间的嵌入${\mathrm{铂硒}}_2$和硒化过程中的铂表面。在这种情况下，硒钝化表面与${\mathrm{铂硒}}_2$ 被发现是 $3.24\text{一种}$，这与可以从混合系统的扫描透射电子显微镜图像中提取的距离一致，并且发现吸附能落在物理吸附范围内。因此，我们的发现提供了对${\mathrm{铂硒}}_2$ 通过直接硒化：实际的结构模型应包括硒钝化的表面，而不是干净的表面。