Photostability of Organic Field-Effect Transistors

Fluctuation in channel current in the organic field-effecttransistors(OFETs) under illumination, caused by the photoresponse of the polymerchannel layer, is one of the critical factors influencing the operationalstability of the OFET-based backplane. In this work, a mechanisticstudy of the photostability of the OFETs was carried out. A samplefront-end driving circuit, comprising an OFET and an organic light-emittingdiode unit, was used to analyze the photostability of the OFET underthe illumination of near-infrared (850 nm) light, which correspondsto the peak absorption of the polymer channel layer. The results revealthat photostable OFETs with a negligible change in the channel currentand the threshold voltage can be realized by mitigating the defect-associatedcharge trapping and detrapping processes under illumination, enabledby improved molecular packing in the polymer channel layer. The outcomesof this work provide important insight and OFET design knowledge fora plethora of applications in front-end circuits, image sensors, andflexible displays.