Optimization of chitosan gated electric double layer transistors by combining nanoparticle incorporation and acid doping

Abstract

In this article, we report on the successful implementation of nanoparticle incorporation and acid doping in tuning the properties of chitosan for proton-based ion gating of metal–oxide electric double layer transistors (EDLTs). SiO₂ nanoparticle (nano-SiO₂) incorporation was initially found to produce rougher surfaces, lower the specific capacitance and postpone the transport of protons, which deteriorated the performance of the transistors. The advantage of nano-SiO₂ incorporation lies in their ability to significantly improve the transistor's negative bias stability due to a proposed proton blocking mechanism. By applying doping of H₃PO₄, the negative effects of nano-SiO₂ incorporation were partially counterbalanced. This is because H₃PO₄ can donate more protons and assist the proton conduction via the donor/acceptor process of amphoteric acids or forming the molecular network of hydrogen bonds. Overall, this work presents a promising strategy to optimize the bio-polyelectrolyte gated EDLTs by combining nanoparticle incorporation and acid doping.