Electrochemically-Gated Field-Effect Transistor with Indium Tin Oxide Nanoparticles as Active Layer

An electrochemically-gated junction field-effect transistor with metallic conducting indium tin oxide nanoparticle array as active layer is reported. Fabrication of a field-effect device with a degenerative semiconductor like indium tin oxide (carrier concentration $10^{20}-10^{21} cm^{-3}$) is possible by exploiting the high surface-to-volume ratio of nanoparticles and high surface charge density achievable by electrochemical gating. The on/off ratio obtained is 325 although the applied potential was restricted to the capacitive double layer region (to ensure high repeatability) without allowing redox reactions to take place at the interface.