An all-organic active pixel photosensor featuring ion-gel transistors

Abstract

We report the development of an all-organic active pixel sensor (APS) composed of a poly3-hexylethiophene (P3HT) and phenyl-C61-butryic acid methyl ester (PCBM) organic photodiode (OPD) connected to two organic field effect transistors and present here a study of its electro-optical characteristics. The OPD showed dark currents of 17.5 nA cm−2 with an external quantum efficiency of 30%. Our organic transistors feature UV-curable ion gels to obtain a high-capacitance dielectric with a combination of high electronic mobility, up to 4 cm2 V−1 s−1, and extremely low operating voltage, below 2 V. The APS configuration gives an in-pixel amplification of the photodetector response, with the gain reaching 40 under a 41 mW cm−2 illumination.