In this paper, an improvement in the signal-to-noise (S/N) ratio of a nanocuboid array near-infrared (NIR) photodetector is demonstrated by using a combination of a small Schottky junction area and a converging lens. The combination of the small Schottky junction area and the lens showed a higher S/N ratio than a Schottky area of 1 cm2 for wavelengths above 1.2 μm, indicating 3.5 and 9.5 dB improvements in the S/N ratio at wavelengths of 1.2 and 1.5 μm, respectively. The structural parameters of the nanocuboids were determined to be 600 nm in length, 535 nm in height, and 900 nm in periodicity with high absorption efficiency in the broadband NIR region. The photocurrent signal was obtained over a broadband in the NIR region from 1.1 to 1.5 μm in wavelength by converging light with a convex lens above the nanocuboid array with a Schottky junction area of 1 mm2.

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