High temperature SU-8 pyrolysis for fabrication of carbon electrodes

- The influence of pyrolysis parameters at 1100 °C on pyrolytic carbon electrode properties is investigated.
- Higher pyrolysis temperature leads to electrodes with higher conductivity and improved electrochemistry.
- Dwell time is the most influencing parameter for the electrical and electrochemical properties.
- Heating rate is the most relevant parameter for the thickness after pyrolysis.

In this work, we present the investigation of the pyrolysis parameters at high temperature (1100 °C) for the fabrication of two-dimensional pyrolytic carbon electrodes. The electrodes were fabricated by pyrolysis of lithographically patterned negative epoxy based photoresist SU-8. A central composite experimental design was used to identify the influence of dwell time at the highest pyrolysis temperature and heating rate on electrical, electrochemical and structural properties of the pyrolytic carbon: Van der Pauw sheet resistance measurements, cyclic voltammetry, electrochemical impedance spectroscopy and Raman spectroscopy were used to characterize the pyrolytic carbon.The results show that the temperature increase from 900 °C to 1100 °C improves the electrical and electrochemical properties. At 1100 °C, longer dwell time leads to lower resistivity, while the variation of the pyrolysis parameters has small influence on electrochemical performance.