Return
Quantifying Surface Charge Density by Using an Electric Force Microscope with a Referential Structure
DOI:10.1021/jp806667h.png)
Abstract
En 中文
A comparative method was proposed to quantitatively measure the charge density on sample surfaces at the nanometer scale by using an electric force microscope (EFM). By introducing a millimeter-sized conductive sphere as a charge reference, whose surface charge density was proportional to the applied voltage, the electrostatic interaction between an EFM probe and the-sphere could be calibrated as a function of charge density. Because the Coulombic force acting on the probe is proportional to the linear term of the phase shift (Delta theta) versus tip voltage (V-t) characteristics, the charge density of an unknown sample could be derived by comparing the slopes of the characteristic curves measured on the studied sample with that obtained on the reference sphere whose absolute charge density had been known. The approach was applied to determine the charge density of a freshly cleaved mica surface. The comparative scheme avoids the complex influence from the irregular shape of EFM tips, providing a facile approach for quantitative analysis of the charge density on sample surfaces at the nanometer scale.
Keywords:
INJECTION
PHOTOIONIZATION
VISUALIZATION
MONOLAYERS
DNA
AI Summary
Key information extracted from the uploaded paper, including a brief overview, abstract, background, key highlights, visual analysis, and future outlook.
Journal
IF:
3.2
Papers:
5.6W
Citations:
15.0W

