(2bh) Alkalide-Assisted Direct Electron Injection for the Noninvasive n-Type Doping of Graphene

My previous research was focused on two subjects.

The first study was on the quantification of MALDI mass spectrometry. I demonstrated that the microstructured stamp enabled quantitative analysis of the peptide adsorbed surface by precisely controlling the extraction and concentration of analyte from the defined area of surfaces. Since the wall of the stamp structure preserve spatial information of the adsorbates on the surfaces, and provide uniform and deposition of matrix solution over entire area, quantitative MALDI mass spectrometry imaging was achieved on the biomolecule adsorbed surfaces.

The second study was on the noninvasive n-type doping of graphene. I developed a convenient method for n-type doping of graphene using sodium anion. The details are included in the abstract for presentation.

Currently, I'm working on the development of the nanomaterial-based mass spectrometry plaform for the quantitative analysis of mass spectrometry. The controllable electronic property of the nanomaterials enabled tuning the ion yields in the mass spectrometry.

In the future, I'd like to do research in the interdisciplinary fields of chemistry and materials that can be potentially enlarged to the biomedical applications.

Abstract for presentation

Although the doping of graphene grown by chemical vapor deposition is crucial in graphene-based electronics, non-invasive methods of n-type doping have not been widely investigated in comparison with p-type doping methods. We developed a convenient and robust method for the non-invasive n-type doping of graphene, wherein electrons are directly injected from sodium anions into the graphene. This method involves immersing the graphene in solutions of [K(15-crown-5)₂]Na prepared by dissolving NaK alloy in 15-crown-5 solution. The n-type doping of the graphene was confirmed by down-shifted G and 2D bands in Raman spectra and by the Dirac point shifting to a negative voltage. The electron-injected graphene showed no sign of structural damage, exhibited higher carrier mobilities than that of pristine graphene, and remained n-doped for over a month of storage in air. In addition, we demonstrated that electron injection enhances noncovalent interactions between graphene and metallomacrocycle molecules without requiring a linker, as used in previous studies, suggesting several potential applications of the method in modifying graphene with various functionalities.