Gold nanoparticles-decorated N,N′-dioctyl-3,4,9,10-perylene tetracarboxylic diimide active layer towards remarkably enhanced visible-light photoresponse of an n-type organic phototransistor

Metal nanostructures exhibit distinct physical properties from macroscopic objects, which have been widely applied to organic optoelectmnic device. N, N'-dioctyl-3,4,9,10-perylene tetracarboxylic diimide (PTCDI-C8) is one of the few air-stable, high mobility n-type semiconductor, which is usually used to fabricate green or white light detectors due to its main absorption concentrated in the range 450 - 600 nm. In this paper, a high performance red light sensor was achieved by PTCDI-C8 based organic phototransistor (OPT) with the optimized gold nanoparticles (AuNPs) modified layer, the photosensitivity, photoresponsivity, specific detectivity and the external quantum efficiency (EQE) of which can reach 6.21 x 10(5), 24.12 A/W, 2.85 x 10(11) Jones and 453.58% at 660 nm, respectively. Additionally, the AuNPs-modified OPT also gained a significant improvement in EQE under green light illumination at 532 nm compared with single PTCDI-C8 layer OPT. The photophysical mechanisms of introducing AuNPs to improve device performance were explored.

Automated summary

This paper demonstrates a high-performance red light sensor based on a PTCDI-C8 organic phototransistor with an optimized gold nanoparticles modified layer, which exhibits superior optical properties. The introduction of AuNPs leads to high photosensitivity, photoresponsivity, and external quantum efficiency at 660nm, as well as a significant improvement under 532nm green light illumination compared to single PTCDI-C8 layer OPT. The photophysical mechanisms of introducing AuNPs to improve device performance were explored in this study.