| dc.description.abstract | In this study, the two-step metal-catalyzed electroless etching approach is successfully used to fabricate large-area, vertically-aligned single crystalline silicon nanowire arrays (SiNWs) on (001) silicon substrate. In addition, the double-sided SiNWs are further prepared in this study. The double-sided structure exhibits high broadband absorption from visible to near-infrared (NIR) light range, and the large enhancement in NIR range can be attributed to silver-nanoparticles remaining at the bottom of the SiNWs after two-step etching processes. In the fabrication of the NIR photodetectors, we first develop Au/SiNWs Schottky junction on the origin thick Si substrate. By E-beam evaporation, Au and Al metal thin film are deposited on the top surface of SiNWs, and their morphologies are observed by TEM analysis. The produced Au/SiNWs Schottky junction NIR photodetectors are able to operate at zero external bias voltage and exhibite high responsivity, sensitivity and rapid response time to 940 nm and 1300 nm NIR light.
The flexible Au/SiNWs Schottky junction NIR photodetectors are demonstrated by combining with ultra-thin Si substrate which has excellent bending ability, and it can be applied to achieve detection of NIR light on larger curvature surface. Furthermore, the produced flexible NIR photodetectors exhibit excellent reliability which can withstand several bending cycles. Finally, the mechanisms of photocurrent generation by Au/SiNWs Schottky junction and Ag nanoparticles under NIR light illumination are dicussed, and we successfully developed SiNWs-based NIR photodetector that can directly modulate the photocurrent signal by using different intensity of the NIR light, which is less mentioned in the literature.
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