Ultrafast and self-driven flexible photodetector based on vertical MoS2/Si heterojunction through enhanced light-trapping structures and Al2O3 interface passivation.

[Display omitted] • Self-powered MoS 2 /Si flexible photodetectors with Al 2 O 3 interface were developed. • The vertical MoS 2 nanofilms were grown by RF magnetron sputtering and Al 2 O 3 by ALD. • The photodetectors could be bent up to 120° and worked well after 200 bending times. • R of 0.047 A/W and D* of 5.67 × 1011 Jones were obtained under 980 nm with 200 μW/cm2. The self-driven flexible photodetector is vitally important for next-generation optoelectronics. Two-dimensional (2D) molybdenum sulfide (MoS 2) as a typical family member of transition-metal dichalcogenides (TMDs) has shown larger potential applications in the high-sensitivity photodetection due to its self-physical properties. Herein, the ultrafast MoS 2 /Si flexible photodetector with ultrathin Al 2 O 3 passivation interface and high light-trapping structures was fabricated. The MoS 2 /Al 2 O 3 /Si flexible photodetector exhibits excellent performance with a high responsivity of 0.047 A/W, detectivity up to 5.67 × 1011 Jones and rise/fall time of 25.6/3.2 μs. Furthermore, this optoelectronic device can withstand bending angles of 120° and work well after 500 bending times. This unique performance can be attributed to the flexible Si substrate with good mechanical properties, high-light trapping structures and an Al 2 O 3 passivation interface. This device can find potential applications in e-skins, flexible displays and smart health care. [ABSTRACT FROM AUTHOR]