二维InSe的电子结构与性质调控及强场动力学的理论研究

The two-dimensional (2D) InSe materials have perspective appllications in optoelectronics and nanoelectronics fields for their adjustable energy gaps with the number of layers as well as their high carrier mobilities at room temperature. However, the investigation of 2D InSe is just getting started. We plan to modulate the band structures and optical properties of monolayer and multilayer InSe meeting related applications through van der Waals heterostructures construction. Also, we will study the interaction of ultrafast strong lasers with 2D InSe which provides a new way to generate high-order harmonics. We will systematically explore the physical mechanisms of materials types, stacking patterns, changing layer number and applying strain on the band structures and optical properties of 2D InSe van der Waals heterostructures utilizing the first principle calculations. We will theoretically investigate the HHG superfast dynamics from 2D InSe under a strong laser field by solving the extended semiconductor Bloch equations. We will study the high-order harmonics and current signals generated from monolayer and multilayer as well as different crystral structure InSe in ultrafast strong laser fields with different wavelength, pulse duration, intensity and carrier-envelope phase in order to understanding the physical mechanism of the quantum interference effect among energy bands. The current investigation can provide a theoretical guidance for seeking high-efficiency water splitting materials under solar light and solar photovoltaic material and has a constructive scientific meaning for achieving ultrafast laser-induced current responseand high-intensity attosecond light source in experiments.

二维InSe材料能隙随层数变化可调，具有较高的电子迁移率，在光电子学和纳米电子学等领域具有广泛的应用前景。然而，对于这一材料的研究才刚刚起步。我们计划构建范德华异质结调控二维InSe材料的基本电子和光学性质使其满足相关应用的需求，同时，研究该材料与超强、超快激光相互作用时的高次谐波辐射过程。本项目中，拟采用第一性原理系统研究InSe基范德华异质结随材料种类、堆叠方式、层数的变化以及外加因素对其能带结构和光学性质影响的物理机制，通过求解考虑多能带的半导体布洛赫方程，阐明二维InSe在强场中的超快动力学能带间电子相干机制，深入研究激光波长、脉宽、强度及相位等对不同层数、不同晶体结构的二维InSe材料在超快强激光场中产生电流信号和高次谐波信号的影响，理解其物理本质。该研究不仅为寻找高效光催化分解水和太阳能光伏材料提供理论依据与指导，也将对实现超快光电响应和高强度阿秒光源具有重要指导意义。

二维材料由于结构独特、性能优异，近年来受到科学家们的广泛关注，在未来电子和光电子领域有巨大的应用潜力。单一的二维材料或多或少有一定的性能缺陷，人们发现将两种二维材料堆叠构建出范德华异质结可以避免单一材料的缺陷，同时表现出一些新颖的性能。二维硒化铟（InSe）是一种新型的类石墨烯材料 带隙可以在1.4至2.6 eV范围内调节，该材料具有较高的载流子迁移率。因其巨大的发展潜力而备受关注。因此，我们在二维材料性能优化方面做了一些尝试和探索，研究了单层二维半导体材料InSe和CrS2，以及将两种材料堆叠构建出的InSe/CrS2异质结的能带结构，电荷密度等。此外，施加电场可以调控异质结的带隙值。我们计算了异质结的光吸收谱，可以看出，主要的吸收峰位于600nm附近，在可见光的范围内。这些结果表明，InSe/CrS2 vdWH在未来的光电器件应用中有广阔的应用前景。