Achieving high-responsivity near-infrared detection at room temperature by nano-Schottky junction arrays via a black silicon/platinum contact approach

A room temperature sub-bandgap near-infrared ( λ > 1100 nm ) Si photodetector with high responsivity is achieved. The Si photodetector features black Si made by wet etching Si (100), Si/PtSi nano-Schottky junction arrays made from black Si/Pt contacts, and chemical and field-effect passivation of black Si. Responsivities are 147.6, 292.8, and 478.2 mA/W at reverse voltages of − 1.0 , − 1.5 , and − 2.0 V for 1550 nm light, respectively, with corresponding specific detectivities being 9.79 × 10 8 , 1.88 × 10 9 , and 2.97 × 10 9 cm · Hz 1 / 2 / W . This work demonstrates a practical room temperature sub-bandgap near-infrared Si photodetector that can be made in a facile and large-scale manner.