Ultra-fast interfacial charge transfer probed using a core-hole clock implementation of resonant inelastic x-ray scattering (RIXS)

使用共振非弹性 X 射线散射 (RIXS) 的芯孔时钟实现探测超快界面电荷转移

基本信息

批准号：
EP/T004355/1
负责人：
James O'Shea
金额：
$ 2.67万
依托单位：
University of Nottingham
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2019
资助国家：
英国
起止时间：
2019 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=EP%2FT004355%2F1
关键词：
Ultra fast interfacial charge transfer

项目摘要

Ultra-fast electron transfer between a molecule and a surface to which it is coupled plays a key role in light-harvesting devices such as dye-sensitised solar cells and water-splitting photoelectrochemical cells (the model water splitting photoanode shown in figure 1 being a prime example). An elegant way to probe these charge transfer processes, which typically happen on the low femtosecond timescale is the use of resonant core-level spectroscopy in the form of resonant photoemission (RPES). This non-radiative core-hole decay technique relies on monitoring the photoelectrons emitted when a resonantly excited electron participates in the core-hole decay. But these have a very limited escape depth so the technique can only be applied to systems where the charge transfer interface is the surface. In principle, the photons emitted during core-hole decay carry the same information. The corresponding radiative technique is known as resonant inelastic x-ray scattering (RIXS).The aim of this proposal is to realise a novel core-hole clock implementation of resonant inelastic x-ray scattering (RIXS) to probe the electron transfer from specific unoccupied molecular orbitals of a dye molecule into the conduction band of a surface to which it is adsorbed. Using this method we should be able to probe charge transfer dynamics on the timescale of the core-hole lifetime (a few femtoseconds) in the same way as resonant photoemission (RPES), only here we are using a photons-in, photons-out technique. This approach is a very promising route to probing ultra-fast charge transfer in realistic systems where the charge transfer interface of molecular devices such as solar cells are typically buried by a transport layer or electrolyte. The series of synchrotron experiments described in this overseas travel grant proposal aim to obtain the data for a definitive reconciliation of the core-hole clock implementations of both RPES and RIXS, and the application of the latter to a buried charge transfer interface.

超快速的电子在分子和与之耦合的表面之间的转移在轻度收获的设备（例如染料敏化的太阳能电池和散滴光光学化学细胞）中起着关键作用（图1中显示的模型水拆卸光阳极是一个主要的示例）。探测这些电荷传输过程的一种优雅方法，通常发生在低飞秒时间尺度上，这是使用谐振光发射（RPE）形式的谐振核心水平光谱。这种非辐射性核心 - 孔衰减技术依赖于监测当备件激发的电子参与核心孔衰减时发出的光电子。但是这些具有非常有限的逃生深度，因此该技术只能应用于电荷传递界面为表面的系统。原则上，核心衰减期间发出的光子带有相同的信息。相应的辐射技术被称为谐振非弹性X射线散射（RIX）。该提议的目的是实现一个新颖的核心孔时钟实现，其谐振不弹性X射线散射（RIX）以探测电子从特定的无脑分子孔的dye Molecules of dye Molecule的分子孔的转移到表面的导管，以使其成为表面的传感器。使用此方法，我们应该能够以与谐振光发射（RPES）相同的方式探测核心孔寿命（几次飞秒）时间尺度上的电荷传输动力学，只有在这里我们使用的是光子输入，光子输出技术。这种方法是在现实系统中探测超快速电荷转移的非常有前途的途径，在现实的系统中，分子设备（例如太阳能电池）的电荷传递界面通常被传输层或电解质埋葬。此海外旅行赠款提案中描述的一系列同步实验旨在获得对RPE和RIX的核心孔时钟实现的确定对帐的数据，并将后者应用于埋藏的电荷传输界面。