Palacios-Lidón Elisa, Colchero Jaime, Ortuno Miguel, Colom Eduardo, Benito Ana M, Maser Wolfgang K, Somoza Andrés M
Departamento Física, Edificio CIOyN (Campus Espinardo), Universidad de Murcia, E-30100 Murcia, Spain.
Instituto de Carboquímica (ICB-CSIC), E-500018 Zaragoza, Spain.
ACS Mater Lett. 2021 Dec 6;3(12):1826-1831. doi: 10.1021/acsmaterialslett.1c00550. Epub 2021 Nov 22.
Graphene oxide (GO) is widely used as a component in thin film optoelectronic device structures for practical reasons because its electronic and optical properties can be controlled. Progress critically depends on elucidating the nanoscale electronic structure of GO. However, direct experimental access is challenging because of its disordered and nonconductive character. Here, we quantitatively mapped the nanoscopic charge distribution and charge dynamics of an individual GO sheet by using Kelvin probe force microscopy (KPFM). Charge domains are identified, presenting important charge interactions below distances of 20 nm. Charge dynamics with very long relaxation times of at least several hours and a logarithmic decay of the time correlation function are in excellent agreement with Monte Carlo simulations, revealing an universal hopping transport mechanism best described by Efros-Shklovskii's law.
由于氧化石墨烯（GO）的电子和光学性质可以被控制，出于实际应用的原因，它被广泛用作薄膜光电器件结构的组成部分。进展关键取决于阐明GO的纳米级电子结构。然而，由于其无序和非导电特性，直接进行实验研究具有挑战性。在这里，我们使用开尔文探针力显微镜（KPFM）定量绘制了单个GO片的纳米级电荷分布和电荷动力学。识别出了电荷域，显示出在20纳米以下距离存在重要的电荷相互作用。具有至少数小时的非常长弛豫时间以及时间相关函数呈对数衰减的电荷动力学与蒙特卡罗模拟结果高度吻合，揭示了一种由Efros-Shklovskii定律最佳描述的通用跳跃传输机制。
