Functionalizing LAyered 2D nanoflakes for Tailored optoelectronics

2D材料为纳米光电子学提供了一个多功能的游乐场：不同的单原子厚材料提供了各种各样的光学特性。由这种材料支持的感兴趣的效应是独特的光吸收，从微波到紫外频率的光的转换或发射，通过超快门控控制电荷迁移率的能力，引入缺陷以发射用于量子应用的光子，或电子学的新机会。当不同的单层材料堆叠时，形成具有可通过设计控制的特性的人工异质结构。例如，将石墨烯与六方氮化硼单层组合允许调节石墨烯的电子结构及其能带。异质结构结合不同的二维材料，使微尺度的发光和光电器件。拓扑极化激元发生在双层过渡金属dichalcogenides和声子极化激元从双曲到非双曲色散关系的转变发生在扭曲MoO 3 bilayers.While这些属性中的一些已经探索了无限层，我们的项目探讨了二维材料薄片和薄片基异质结构的光电潜力。我们的工作的独特之处是描述与紧束缚的方法，以适应与纳米结构中的量子限制相关的影响，结合时间相关的密度矩阵的描述。一个主方程解释了薄片电子在用外部光源或电门控照射时的演化，包括由电子-电子相互作用或缺陷的存在引起的效应。 我们将开发一个量子力学框架来模拟不同材料薄片中电磁照射下的电子动力学，并将其应用于了解它们在基础水平上的光电特性。扩展该框架以允许堆叠由不同材料制成的元件。扩展的方法将被应用于设计可调电子特性和光学响应的器件，例如电光调制器，极化电路或光学传感器。进行这些结构中的电子动力学及其在光学和光电子学中的应用的全面研究。我们专注于具有经典特性或量子统计的基于纳米片的发光器件的应用。通过组合或旋转几个材料薄片，我们将设计这些光源的光谱特性及其方向性。我们将探索基于纳米片或带的这种源的能量特性如何依赖于外部电门控，并利用这些信息进一步发展我们对微型电光调制器的贡献。我们将研究纳米尺度可调隧道晶体管中的电子隧穿穿过纳米片或纳米带中的绝缘势垒。

2D materials provide a versatile playground for nanoscale optoelectronics: different single-atom thick materials offer a great variety of optical properties. Effects of interest supported by such materials are a unique optical absorption, the transduction or emission of light from microwave to ultraviolet frequencies, the ability to control the charge mobility by ultrafast gating, the incorporation of defects to emit photons for quantum applications, or novel opportunities for electronics.Whole new potentials unfolds when different monolayered materials are stacked, forming artificial heterostructures of properties controllable by design. For example, combining a graphene with a hexagonal boron nitride monolayer allows to modulate graphene's electronic structure and its energy band. Heterostructures combining different 2D materials make microscaled light emitting and optoelectronic devices. Topological polaritons occur in bilayer transition metal dichalcogenides and a transition from a hyperbolic to a non-hyperbolic dispersion relation for phonon polaritons occurs in twisted MoO3 bilayers.While some of these properties have been explored for infinite layers, our project explores the optoelectronic potential of 2D material flakes and flake-based heterostructures. Unique to our work is the description with a tight-binding methodology to accommodate effects related to the quantum confinement in the nanostructures, combined with a description in terms of time-dependent density matrix. A master equation accounts for the evolution of flake electrons upon illumination with external light sources or electric gating, including effects resulting from electron-electron interactions or presence of defects. We will-develop a quantum-mechanical framework to model electron dynamics under electromagnetic illumination in different material flakes and apply it to understand their optoelectronic properties at the fundamental level.-extend this framework to allow stacking of elements made of different materials. The extended method will be applied to design devices of tunable electronic properties and optical response, e.g. electro-optic modulators, polaritonic circuits, or optical sensors.-perform a comprehensive study of electron dynamics in these structures and their applications for optics and optoelectronics.The applications we concentrate on are nanoflake-based light emitting devices with classical characteristics or with quantum statistics. By combining or rotating several material flakes we will engineer the spectral properties of these sources and their directionality. We will explore how the energy characteristics of such sources based on nanoflakes or ribbons rely on external electric gating, and exploit that information to develop our contribution further towards miniaturized electro-optic modulators. We will study the electron tunnelling through insulating barriers in nanoflakes or ribbons for nanoscaled tunable tunnel transistors.