Towards high performance broad spectral response fullerene based photosensitive organic field-effect transistors with tricomponent bulk heterojunctions

Abstract

Recently, broad spectral response phototransistors have drawn substantial attention due to their applications in the field of industry and science. However, it is difficult to synthesize appropriate photosensitive materials, which greatly limits their development. Integrating multicomponent bulk heterojunctions with high mobility materials to form hybrid planar-bulk heterojunction is a very effective approach to overcome these shortcomings. Herein, we reported broad spectral response photosensitive organic field-effect transistors with tricomponent bulk heterojunctions (Tri-BHJ) and high mobility channel transport layer, and they were sensitive over a bandwidth from ultraviolet–visible to near infrared. The Tri-BHJ composed of 3,4,9,10-perylenetetracarboxylic dianhydride (PTCDA), chloroaluminum phthalocyanine (AlClPc) and lead phthalocyanine (PbPc) was used as the photosensitive layer, fullerene (C60) as the channel layer, and SiO2 as the gate dielectric. By replacing SiO2 with polyvinyl alcohol (PVA), the device performance was improved significantly, and the photosensitivity, photoresponsivity, external quantum efficiency and specific detectivity of the device built on PVA dielectric reached up to 105, 108.44 A/W, 25325% and ∼2.7 × 1012 Jones, respectively, which are comparable or even superior to those of commercially silicon and indium gallium arsenide photodetectors or other reported organic photodetectors. This work indicated new directions for the future development of high performance broad spectral response phototransistors.