Very small metallic nanostructures,i.e.,plasmonic nanoparticles(NPs),can demonstrate the localized surface plasmon resonance(LSPR)e ect,a characteristic of the strong light absorption,scattering and localized electrom...Very small metallic nanostructures,i.e.,plasmonic nanoparticles(NPs),can demonstrate the localized surface plasmon resonance(LSPR)e ect,a characteristic of the strong light absorption,scattering and localized electromagnetic field via the collective oscillation of surface electrons upon on the excitation by the incident photons.The LSPR of plasmonic NPs can significantly improve the photoresponse of the photodetectors.In this work,significantly enhanced photoresponse of UV photodetectors is demonstrated by the incorporation of various plasmonic NPs in the detector architecture.Various size and elemental composition of monometallic Ag and Au NPs,as well as bimetallic alloy Ag Au NPs,are fabricated on Ga N(0001)by the solid-state dewetting approach.The photoresponse of various NPs are tailored based on the geometric and elemental evolution of NPs,resulting in the highly enhanced photoresponsivity of 112 A W-1,detectivity of 2.4×1012 Jones and external quantum e ciency of 3.6×104%with the high Ag percentage of Ag Au alloy NPs at a low bias of 0.1 V.The Ag Au alloy NP detector also demonstrates a fast photoresponse with the relatively short rise and fall time of less than 160 and 630 ms,respectively.The improved photoresponse with the Ag Au alloy NPs is correlated with the simultaneous e ect of strong plasmon absorption and scattering,increased injection of hot electrons into the Ga N conduction band and reduced barrier height at the alloy NPs/Ga N interface.展开更多
基金Financial support from the National Research Foundation of Korea(NRF)Grant funded by the Korean Government(MSIP)(Nos.NRF-2019R1A2C4069438 and NRF-2018R1A6A1A03025242)in part by the research grant of Kwangwoon University in 2020.
文摘Very small metallic nanostructures,i.e.,plasmonic nanoparticles(NPs),can demonstrate the localized surface plasmon resonance(LSPR)e ect,a characteristic of the strong light absorption,scattering and localized electromagnetic field via the collective oscillation of surface electrons upon on the excitation by the incident photons.The LSPR of plasmonic NPs can significantly improve the photoresponse of the photodetectors.In this work,significantly enhanced photoresponse of UV photodetectors is demonstrated by the incorporation of various plasmonic NPs in the detector architecture.Various size and elemental composition of monometallic Ag and Au NPs,as well as bimetallic alloy Ag Au NPs,are fabricated on Ga N(0001)by the solid-state dewetting approach.The photoresponse of various NPs are tailored based on the geometric and elemental evolution of NPs,resulting in the highly enhanced photoresponsivity of 112 A W-1,detectivity of 2.4×1012 Jones and external quantum e ciency of 3.6×104%with the high Ag percentage of Ag Au alloy NPs at a low bias of 0.1 V.The Ag Au alloy NP detector also demonstrates a fast photoresponse with the relatively short rise and fall time of less than 160 and 630 ms,respectively.The improved photoresponse with the Ag Au alloy NPs is correlated with the simultaneous e ect of strong plasmon absorption and scattering,increased injection of hot electrons into the Ga N conduction band and reduced barrier height at the alloy NPs/Ga N interface.
