The novel two-dimensional (2D) semiconductor, InSe, with tunable band gap and high electron mobility, has attracted increasing research interest. In this work, we demonstrate theoretically the strong geometry confinement in InSe quantum dots (QD) and manipulate their electronic and optical properties using QD shape and external field. The electronic energy levels, density of states, probability density of states and magneto-optical absorption spectra, are calculated by utilizing the tight-binding method with Coulomb interaction in the Hubbard model. In contrast to other 2D materials, e.g. phosphorene, InSe-QDs exhibit distinct features as (a) edge states appear in the bottom of the conduction band regardless of the shapes of InSe-QDs; (b) the edge states are mainly provided by the In atoms at the both armchair and zigzag edges in InSe-QDs; (c) optical gap is distinct from band gap. The rectangular InSe-QDs produce anisotropic optical absorption spectra, whereas hexagonal and triangular InSe-QDs produce isotropic absorption spectra. The applied magnetic field would weaken this anisotropy.

具有可调带隙和高电子迁移率的新型二维 (2D) 半导体 InSe 引起了越来越多的研究兴趣。在这项工作中，我们从理论上证明了 InSe 量子点 (QD) 中的强几何限制，并使用 QD 形状和外场操纵它们的电子和光学特性。电子能级、态密度、态概率密度和磁光吸收光谱是利用哈伯德模型中库仑相互作用的紧束缚方法计算出来的。与其他二维材料（例如磷烯）相比，InSe-QD 表现出明显的特征，因为（a）边缘态出现在导带底部，而与 InSe-QD 的形状无关；(b) 边缘态主要由 InSe-QD 中扶手椅和锯齿形边缘的 In 原子提供；(c) 光隙不同于带隙。矩形 InSe-QDs 产生各向异性的光学吸收光谱，而六角形和三角形的 InSe-QDs 产生各向同性的吸收光谱。施加的磁场会削弱这种各向异性。