Transparent, Broadband, Flexible, and Bifacial-Operable Photodetectors Containing a Large-Area Graphene–Gold Oxide Heterojunction

Abstract

In this study, we combine graphene with gold oxide (AuOx), a transparent and high-work-function electrode material, to achieve a high-efficient, low-bias, large-area, flexible, transparent, broadband, and bifacial-operable photodetector. The photodetector operates through hot electrons being generated in the graphene and charge separation occurring at the AuOx-graphene heterojunction. The large-area graphene covering the AuOx electrode efficiently prevented reduction of its surface; it also acted as a square-centimeter-scale active area for light harvesting and photodetection. Our graphene/AuOx photodetector displays high responsivity under low-intensity light illumination, demonstrating picowatt sensitivity in the ultraviolet regime and nanowatt sensitivity in the infrared regime for optical telecommunication. In addition, this photodetector not only exhibited broadband (from UV to IR) high responsivity-3300 A W(-1) at 310 nm (UV), 58 A W(-1) at 500 nm (visible), and 9 A W(-1) at 1550 nm (IR)-but also required only a low applied bias (0.1 V). The hot-carrier-assisted photoresponse was excellent, especially in the short-wavelength regime. In addition, the graphene/AuOx photodetector exhibited great flexibility and stability. Moreover, such vertical heterojunction-based graphene/AuOx photodetectors should be compatible with other transparent optoelectronic devices, suggesting applications in flexible and wearable optoelectronic technologies.

High-performance flexible and broadband photodetectors based on PbS quantum dots/ZnO nanoparticles heterostructure

“…Many kinds of flexible broadband photodetectors based on pure semiconductors or composite nanostructures have been carefully investigated [13,14]. Recently, some efforts have been made to enhance the performance of the flexible photodetector by forming inorganic AuO x /graphene and organic/inorganic perovskite/ZnO nanowire hybrid structure [15,16]. However, the active materials (graphene and ZnO nanowires) of the photodevices were synthesized via high temperature physical evaporation route.…”

Slot‐Die‐Coated V2O5 as Hole Transport Layer for Flexible Organic Solar Cells and Optoelectronic Devices

“…The optimized layers are applied and tested in flexible organic solar cell devices of commonly reported architecture produced using roll coating machinery. Additionally, by expanding the applicability of our findings we show that the HTLs with V 2 O 5 can be applied successfully in the emerging new field of organic photodetectors (OPD) . We fabricate flexible OPD devices with industrial‐scale manufacturing techniques such as slot‐die coating and demonstrate their use in proximity and light‐sensing applications.…”

Flexible and Stretchable Optoelectronic Devices using Silver Nanowires and Graphene

“…Liu et al combined graphene with gold oxide to enhance the operation quality of photodetectors. [ 35 ] Even though graphene has a large density of carriers, the gapless nature of graphene meant that a a high dark current was produced. Here, graphene generated hot electrons by light exposure, and then the gold oxide effectively separated the charges at the gold-oxide-graphene heterojunction.…”