High-performance organic thin-film phototransistors based on stacked p–n heterojunctions for enhanced optoelectronic response†

Abstract

This research mainly focuses on utilizing the characteristics of organic semiconductor materials to design and fabricate high-performance organic thin-film phototransistors. The semiconductor materials employed include the n-type semiconductor N,N′-ditridecylperylene-3,4,9,10-tetracarboxydiimide (PTCDI-C₁₃) and the p-type semiconductor pentacene. These p- and n-type semiconductors are arranged in a tandem structure to form the active layer of the device, creating a heterojunction interface. The tandem structure offers the advantage of enabling the device to exhibit excellent light absorption capabilities across the entire visible light spectrum (400–700 nm). When light illuminates the channel of the active layer, excitons are generated in the semiconductor materials. The heterojunction interface can provide a built-in electric field, which facilitates the dissociation of excitons and charge transport, enabling the photogenerated charge carriers to be effectively collected. This significantly enhances the photosensitivity and photoresponsivity performances, far exceeding those of a single semiconductor layer. Overall, this research has successfully developed a high-performance organic thin-film phototransistor, which has important implications for the development of new optoelectronic devices and applications.