High performance ambipolar response photodetectors based on ReS2/PdSe2 van der Waals heterostructures

• Published in: Materials today communications 2024-08, Vol.40, p.109945, Article 109945
• Main Authors: Li, Peipei, Sun, Yurun, Gao, Xingguo, Meng, Yan, Ma, Jun, Wang, Junmei, Gao, Honglei, Du, Changhui, Wang, Wenjia, Li, Kuilong
• Format: Article
• Language: English
• Subjects: Ambipolar photoresponse; External quantum efficiency; ReS2/PdSe2 heterostructure; Responsivity
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2024.109945

Anomalous negative photoresponse in a photodetector where the current is reduced under light illumination holds great potential in the application of next-generation novel and multifunctional optoelectronic devices. Until now, the figure of merits for negative photodetectors, such as responsivity and response speed, still exhibit unsatisfactory performance when compared to their positive counterparts. In this work, an unique gate voltage-dependent ambipolar-response photodetector based on the ReS2/PdSe2 heterostructure with excellent characteristics are prepared and investigated systematically. The evolution for concentration of hole in PdSe2 by gate voltage and the trap states existed at the surface and interface play a dominant role in the transition of negative to positive response. The negative photoresponse performances in terms of responsivity, external quantum efficiency (EQE), and response speed under 638 nm light illumination, are as high as about 532 A/W, 105%, and as fast as 7.9/8.7 µs, respectively. Meanwhile, the corresponding values of the positive response also reach to ∼10.5 A/W, ∼2069 %, and ∼30 µs, respectively, demonstrating the superiority of this heterostructure at ambipolar response. In addition, a similar phenomenon is also observed at the near-infrared region (980 nm). The discovery of these results signifies a pronounced breakthrough in the field of ambipolar photodetectors, thereby paving the way for future advancements in optoelectronic applications. [Display omitted] •High performance gate voltage dependent ambipolar response was achieved in ReS2/PdSe2 photodetectors.•The negative photoresponse responsivity under 638 nm light illumination is as high as about 532 A/W.•The response speed of negative photoresponse is as fast as 7.9/8.7 µs.•The positive response also shows excellent performances.