IGZO Phototransistor with Ultrahigh Sensitivity at Broad Spectrum Range (450–950 nm) Realized by Incorporating PM6:Y6 Bulk Heterojunction

Abstract

Among various photoresponsive materials, organic materials have gained interest due to their low cost, large-scale yields, and compatibility with flexible substrates. However, their low photoresponsivity compared to inorganic counterparts has been consistently pointed out as a limitation. To address this issue, a highly photoresponsive PM6:Y6/IGZO hybrid phototransistor is presented with a broad spectral range of 450–950 nm. The photoresponse of the device is enhanced by controlling the PM6:Y6 blending ratio, active layer thickness, and solvent additive treatment. The PM6:Y6 blending ratio and thickness are optimized to promote charge separation and efficient charge transport, leading to a significant increase in photoresponsivity. Moreover, solvent additives are employed to improve the crystallinity of the PM6:Y6 film, which further enhanced the charge transport. As a result, the PM6:Y6/IGZO hybrid phototransistor exhibited exceptional performance, with an ultrahigh photoresponsivity of 2.2 × 108 A W−1 and specific detectivity of 9.8 × 1016 Jones under 750 nm light with an intensity of only 1.03 nW cm−2. These results highlight the potential of organic materials in developing high-performance phototransistors. © 2024 Wiley-VCH GmbH.