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.

Keywords:

• active pixel sensor
• organic field effect transistor
• organic photosensor
• P3HT
• PCBM
• ion-gel dielectric

Acknowledgements

We acknowledge the Australian Research Council (FT0990285). This work was performed in part using the NSW node of the Australian National Fabrication Facility (ANFF).

Disclosure Statement

No potential conflict of interest was reported by the author(s).