Selective Deposition of N-Heterocyclic Carbene Monolayers on Designated Au Microelectrodes within an Electrode Array

Small. 2024 Jan;20(2):e2302317. doi: 10.1002/smll.202302317. Epub 2023 Sep 4.

Abstract

The incorporation of organic self-assembled monolayers (SAMs) in microelectronic devices requires precise spatial control over the self-assembly process. In this work, selective deposition of N-heterocyclic carbenes (NHCs) on specific electrodes within a two-microelectrode array is achieved by using pulsed electrodeposition. Spectroscopic analysis of the NHC-coated electrode arrays reveals that each electrode is selectively coated with a designated NHC. The impact of NHC monolayers on the electrodes' work function is quantified using Kelvin probe force microscopy. These measurements demonstrate that the work function values of each electrode can be independently tuned by the adsorption of a specific NHC. The presented deposition method enables to selectively coat designated microelectrodes in an electrode array with chosen NHC monolayers for tuning their chemical and electronic functionality.

Keywords: N-heterocyclic carbenes; monolayers; surface analysis; surface chemistry.