RESUMO
In this article, we fabricated a sensitive near-infrared (NIR) light detector by directly coating a layer of Cs-doped FAPbI3 perovskite film onto vertical Si nanowire (SiNW) array. The as-assembled SiNW array/perovskite core-shell heterojunction exhibits a typical rectifying characteristic in darkness and distinct photoresponse characteristics under light illumination. Owning to the remarkable photovoltaic effect, the heterojunction can work as a self-driven NIR detector without an exterior energy supply. Further photoresponse investigation reveals that the photodetector is sensitive in a wide wavelength range with maximum sensitivity at â¼850 nm. The responsivity ( R) and specific detectivity ( D*) are estimated to be 14.86 mA W-1 and 2.04 × 1010 Jones at 0 V bias, respectively, which can be improved to 844.33 mA W-1 and 3.2 × 1011 Jones at a bias voltage of -0.9 V. In addition, the present device also possesses distinct advantages of a large Ilight/ Idark ratio exceeding 104, swift response rate with rise/decay times of 4/8 µs, and relatively good ambient stability. According to our numerical simulation based on finite element method, the superior device performance is associated with strong light-trapping effect in such unique core-shell heterojunction array.
RESUMO
In this study, we present a broadband nano-photodetector based on single-layer graphene (SLG)-carbon nanotube thin film (CNTF) Schottky junction. It was found that the as-fabricated device exhibited obvious sensitivity to a wide range of illumination, with peak sensitivity at 600 and 920 nm. In addition, the SLG-CNTF device had a fast response speed (τr = 68 µs, τf = 78 µs) and good reproducibility in a wide range of switching frequencies (50-5400 Hz). The on-off ratio, responsivity, and detectivity of the device were estimated to be 1 × 102, 209 mAW-1 and 4.87 × 1010 cm Hz1/2 W-1, respectively. What is more, other device parameters including linear performance θ and linear dynamic range (LDR) were calculated to be 0.99 and 58.8 dB, respectively, which were relatively better than other carbon nanotube based devices. The totality of the above study signifies that the present SLG-CNTF Schottky junction broadband nano-photodetector may have promising application in future nano-optoelectronic devices and systems.
RESUMO
A deep UV light photodetector is assembled by coating multilayer graphene on beta-gallium oxide (ß-Ga2 O3 ) wafer. Optoelectronic analysis reveals that the heterojunction device is virtually blind to light illumination with wavelength longer than 280 nm, but is highly sensitive to 254 nm light with very good stability and reproducibility.
