论文标题
将表面电子带结构与热电子诱导分子纳米探针实验的电压依赖性联系起来的自洽模型
A self-consistent model to link surface electronic band structure to the voltage dependence of hot electron induced molecular nanoprobe experiments
论文作者
论文摘要
在太阳能电池和晶体管等应用上，了解热荷载流子的超快速运输特性在根本上和技术上都至关重要。但是，在相关的纳米长度尺度上直接测量电荷传输是具有挑战性的，迄今为止仅显示了一些实验方法。在这里，我们报告了在室温下在Si（111）-7x7上进行的分子纳米探针实验，在室温下，从扫描隧道显微镜（STM）的尖端注入电荷，从表面横向传播，并诱导单个崇拜者甲苯分子分子，以在纳米尺寸的紧张量表上反应。开发了一个简单的模型，用于捕获到每个表面电子带中的隧道电流的比例，并从清洁SI（111）-7x7表面的高分辨率扫描隧道光谱（STS）输入。该模型通过每个状态的单个操纵概率（即拟合参数）定量地与分子纳米探针实验的电压依赖性相关。该模型符合测量的数据，并为测得的电压打击，测量的操作概率的指数增加以及在较高电压下的平稳性提供了解释。它还证实了向表带的底部的超快松弛，用于注射后的注入电荷，但在非本地散布到整个表面之前。
Understanding the ultra-fast transport properties of hot charge carriers is of significant importance both fundamentally and technically in applications like solar cells and transistors. However, direct measurement of charge transport at the relevant nanometre length scales is challenging with only a few experimental methods demonstrated to date. Here we report on molecular nanoprobe experiments on the Si(111)-7x7 at room temperature where charge injected from the tip of a scanning tunnelling microscope (STM) travels laterally across a surface and induces single adorbate toluene molecules to react over length scales of tens of nanometres. A simple model is developed for the fraction of the tunnelling current captured into each of the surface electronic bands with input from only high-resolution scanning tunnelling spectroscopy (STS) of the clean Si(111)-7x7 surface. This model is quantitatively linked to the voltage dependence of the molecular nanoprobe experiments through a single manipulation probability (i.e. fitting parameter) per state. This model fits the measured data and gives explanation to the measured voltage onsets, exponential increase in the measured manipulation probabilities and plateau at higher voltages. It also confirms an ultrafast relaxation to the bottom of a surface band for the injected charge after injection, but before the nonlocal spread across the surface.
