Oxide-based Synaptic Transistors Gated by Solid Biopolymer Electrolytes

In this study, indium–gallium–zinc–oxide (IGZO) synaptic transistors gated by solid biopolymer electrolytes (SBEs) were fabricated on glass substrates. Ammonium bromide (NH 4 Br) was first doped in SBE-based alginate as the gate dielectric to study the performances of synaptic transistors. With the NH 4 Br doping, a high electric-double-layer capacitance of ~ 6.4 μF cm −2 was obtained for the biopolymer electrolyte, which could be attributed to the incorporation of excess protons into the electrolyte from the complexation between alginate and NH 4 Br. Moreover, synaptic functions based on this IGZO transistor gated by NH 4 Br-doped alginate were successfully emulated, including excitatory post-synaptic current, paired-pulse facilitation and post-tetanic potentiation. The present results may provide a solution for the performance improvements of synaptic electronics.