Threshold-voltage tuning characteristics of all-organic electrochemical vertical rectifiers on flexible substrates

A printed all-organic electrochemical vertical tunable rectifier is demonstrated using a conducting polymer as the active material on a flexible plastic substrate. Solution processable poly(3,4-ethylenedioxythiophene) combined with poly(styrene sulfonic acid) (PEDOT:PSS) was coated on polyester film; the rectifier channel was patterned on the PEDOT:PSS film through directly writing technique without the need for masks, patterns, or dies. A vertically layered electrochemical cell was structured via printing and laminating processes to reduce driving voltages. The resulting rectifier is a three-terminal device; the functionality of threshold voltage tuning is realized by adjusting the potential difference within the electrochemical cell. The driving voltages are reduced significantly compared to rectifiers with lateral device architecture. In a single device, the threshold voltage is tunable between 0.16 and 1.0 V while a bias voltage is swept from 0.9 to 1.7 V.