Characterisation of SU-8 n-doping carbon nanotube-based electronic devices

Triarylium-solphonium salt, the chemical component of the SU-8 photo resist, has been proved as an effective n-doping source for graphene. In this reported work, a study has been made of the effects of SU-8 on single walled carbon nanotube networks. The results indicate that SU-8 behaves as an electrons donor and causes an upward shift in the Fermi level. The cross-linking property of the SU-8 resembles an efficient isolator from the oxygen of the ambient. This leads to ambient-stability of this doping technique. In addition, the doping technique shows negligible defects on the CNT surface and then higher transconductance is expected to be achieved. The temperature dependence of the Raman spectra of the CNT network observed a downshift in the G-band with increasing temperature. Finally, since SU-8 is an e-beam sensitive resist as well as a photo resist, it was used to selectively dope CNTs within the substrate area.