# Femtosecond laser patterning of graphene electrodes for thin-film transistors

## TL;DR

This study demonstrates that femtosecond laser patterning of graphene electrodes in vacuum reduces debris and significantly improves the performance of thin-film transistors, including mobility and hysteresis reduction.

## Contribution

It provides a comparative analysis of laser patterning in air versus vacuum, showing vacuum processing yields cleaner graphene and better TFT performance.

## Key findings

- Vacuum laser patterning reduces debris on graphene.
- TFT mobility increases by an order of magnitude.
- Hysteresis disappears and subthreshold swing improves.

## Abstract

The aim of this study is to assess femtosecond laser patterning of graphene in air and in vacuum for the application as source and drain electrodes in thin-film transistors (TFTs). The analysis of the laser-patterned graphene with scanning electron microscopy, atomic force microscopy and Raman spectroscopy showed that processing in vacuum leads to less debris formation and thus re-deposited carbonaceous material on the sample compared to laser processing in air. It was found that the debris reduction due to patterning in vacuum improves the TFT characteristics significantly. Hysteresis disappears, the mobility is enhanced by an order of magnitude and the subthreshold swing is reduced from $S_{sub}~=~2.5~\mbox{V/dec}$ to $S_{sub}~=~1.5~\mbox{V/dec}$.