Highly responsive organic near-infrared photodetectors based on a porphyrin small molecule

Abstract

Solution processed organic near-infrared (NIR) photodetectors (PDs) based on a porphyrin small molecule as a donor material and (6,6)-phenyl-C61-butyric acid methyl ester (PC₆₁BM) as an acceptor material are reported. Operating at room temperature, these PDs show a low dark current density of 3.44 nA cm⁻², a broad spectral response from 380 to 960 nm with high external quantum efficiencies around 20% in the NIR region at a bias of 0 V. Detectivities over 10¹² cm H^1/2 W⁻¹ in the whole range from 380 to 930 nm are achieved, which rank as one of the best performances among previously reported NIR PDs.