Ultra-Sensitive Narrow-Band P-Si Schottky Photodetector With Good Wavelength Selectivity and Low Driving Voltage

Narrowband photodetectors have attracted considerable attention owing to their ability to suppress interference from nontarget wavelengths. However, operation of sensitive narrowband detection usually requires a high driving voltage, which leads to high power consumption and severe degradation of device performance. In this study, a narrowband 1050 nm photodetector with high sensitivity and excellent wavelength selectivity was realized using a simple ${p}$ -type Si Schottky junction. The device exhibited a high responsivity of 810 mA/W and a large linear dynamic range of 128 dB at zero bias. At a low bias voltage of −3 V, its external quantum efficiency increased to ${6}.{9}\times {10} ^{{3}}$ %, with a full width at half maximum of approximately 74 nm. This outstanding device performance can be ascribed to the unique geometry of dual Ti /Ag Schottky electrode and the gain mechanism derived from the large transit-time difference between the photogenerated electrons and holes. This study opens new avenues for the development of highly sensitive narrowband photodetectors with low driving voltages in the future.