Transparent organic photodiodes for high-detectivity CMOS image sensors

Abstract

The demand for high-definition complementary metal-oxide–semiconductor (CMOS) image sensors has increased considerably over the past few years in industry as well as in academia. Here we propose transparent green-sensitive organic photodetectors (TG-OPDs) with both dark-current-based high detectivity (over 10 14 c m H z 1 / 2 W − 1 at a wavelength of 550 nm under 3 V) and high responsivity ( 0.34 A W − 1 under 3 V) for organic–silicon hybrid CMOS image sensors. A b a t h o c u p r o i n e : C 60 electron-transporting layer provided the fabricated TG-OPDs with a minimal junction resistivity, smooth morphology, and desirable energy level modulation, resulting in exceptional light sensitivity, a low dark current (below 10 − 11 A c m − 2 ), and a high rectification ratio spanning 10 orders of magnitude. The TG-OPDs had high-temperature endurance (up to 150°C for 2 h) and operational stability under intense heat (above 85°C) for 50 d. We expect this performance to enable the industrialization of these TG-OPDs for optoelectronic sensor applications, such as photoplethysmography, fingerprint recognition, proximity sensing, and imaging.