论文标题
激光控制电荷转移以二维有机/无机光学连贯纳米结
Laser-Controlled Charge Transfer in a Two-Dimensional Organic/Inorganic Optical Coherent Nanojunction
论文作者
论文摘要
了解统治激光诱导的混合有机/无机接口中的相干电荷转移的基本机制对于在下一代光电应用应用中利用这些系统至关重要。在基于实时时间依赖性密度功能理论的第一原理作品中，我们研究了由摩西$ _2 $单层带有吸附的pyrene pyrene Molecules形成的原型二维垂直纳米结的超快电荷载体动力学。系统对入射脉冲的响应显然是非线性的。在弱脉冲下，电荷转移是从分子到单层的，而强度高于1000 gw/cm $^{2} $，电荷转移的方向被恢复，电子从Mose $ _2 $转移到Pyrene。 Pauli阻止来解释了这一发现：激光诱导的（VANENCE）传导状态的种群饱和200 GW/cm $^{2} $的强度。我们的结果还提供了多光子吸收的证据。对电子电流密度，激发能和激发电子数量的彻底分析支持了拟议的理由，并提出了为超快电子产品创建无机/有机相干光学纳米结的可能性。
Understanding the fundamental mechanisms ruling laser-induced coherent charge transfer in hybrid organic/inorganic interfaces is of paramount importance to exploit these systems in next-generation opto-electronic applications. In a first-principles work based on real-time time-dependent density-functional theory, we investigate the ultrafast charge-carrier dynamics of a prototypical two-dimensional vertical nanojunction formed by a MoSe$_2$ monolayer with adsorbed pyrene molecules. The response of the system to the incident pulse, set in resonance with the frequency of the lowest-energy transition in the physisorbed moieties, is clearly nonlinear. Under weak pulses, charge transfer occurs from the molecules to the monolayer while for intensities higher than 1000 GW/cm$^{2}$, the direction of charge transfer is reverted, with electrons being transferred from MoSe$_2$ to pyrene. This finding is explained by Pauli blocking: laser-induced (de)population of (valence) conduction states saturates for intensities beyond 200 GW/cm$^{2}$. Evidence of multi-photon absorption is also provided by our results. A thorough analysis of electronic current density, excitation energy, and number of excited electrons supports the proposed rationale and suggests the possibility to create an inorganic/organic coherent optical nanojunction for ultrafast electronics.
