High-selectivity NIR amorphous silicon-based plasmonic photodetector at room temperature

Abstract

This study employed amorphous materials to construct a Near-Infrared (NIR) photodetector, enabling optical sensing over a non-crystalline platform. Utilizing an Au/a-Si Schottky junction with an interfacial oxide layer, the device showcased its capability as a NIR photodetector, effectively operating within a wavelength range of up to 1700 nm. Remarkably, it exhibited significant surface plasmon resonance peaks with high selectivity, a full-width at half-maximum of less than 3°, and a sensitivity of −33.3 dBm, demonstrated at room temperature and zero-biasing conditions. Barrier lowering under biasing further increases the device's responsivity by an order of magnitude, revealing absorption capabilities that exceed the material's intrinsic bandgap limitations. This advancement opens the door to developing highly selective detectors using cost-effective amorphous materials and straightforward design. Additionally, a-Si-based photodetectors contribute to environmental preservation as they do not contain toxic heavy metals, establishing them as one of the most Eco-friendly detection solutions.