High-Speed, Self-Biased Broadband Photodetector-Based on a Solution-Processed Ag Nanowire/Si Schottky Junction

In this work, we demonstrate the effectiveness of Ag nanowires (AgNWs) to design a high-speed broadband photodetector. A simple AgNW solution was spin-coated on a Si substrate to form a Schottky junction. The junction properties were investigated using current-voltage characteristics and Mott-Schottky analysis. The present device had a remarkably fast response speed, e.g., rising time τ_r = 784 ns and fall time τ_f = 92 μs, with good reproducibility over a wide range of switching frequencies (50 Hz-50 kHz). Such a high performance was attributed to the strong electric field created at the AgNW/Si interface without an external electric field, enabling the efficient separation of photogenerated electron-hole pairs. The present study will open a new avenue to design future optoelectronic devices and energy devices including solar cells.