Hybrid Graphene/Cu2O Quantum Dot Photodetectors with Ultrahigh Responsivity

Flexible high-sensitivity photodetectors are desirable for use in future wearable optoelectronics. Graphene is attracting considerable attention because of its outstanding electrical, optical, and mechanical properties, which make graphene appealing in flexible optoelectronics and photodetection applications. In this paper, an internal current gain mechanism is proposed based on a 2D/0D photodetection system. The carrier density in the 2D material can be amplified via Fermi level modulation when a 0D quantum dot absorbs photons. An ultrahigh responsivity of more than 10(10) A W-1 and fW-scale light detectivity are achieved at room temperature using the flexible transfer-free hybrid graphene/Cu2O quantum dot photodetector developed in this work. After excessive bending, the responsivity of the photodetector still reaches 10(6) A W-1, thus demonstrating the promising flexibility of the device.