Video-Rate Infrared Focal Plane Array Based on Solution-Processed Black Phosphorus Films

Abstract

Silicon-based complementary metal–oxide–semiconductor integrated circuits have enabled compact and inexpensive high-resolution cameras by efficiently reading the outputs from millions of pixels. For infrared cameras, however, the limited optical absorption of silicon requires the integration of an additional photosensitive material, which is patterned into a focal plane array of pixels and bonded with silicon integrated circuits, adding to the cost and complexity of the imagers. Here, we report an infrared focal plane array based on the direct transfer of a solution-processed black phosphorus film, with photosensitivity extending to mid-infrared wavelengths greater than 3 μm. This approach features a high fabrication yield (>90%) while avoiding expensive flip-chip bonding processes, paving the way for economical mid-infrared imagers. We characterized more than 70,000 functional pixels, which exhibit fast response times (<10 ms) and noise-equivalent irradiances below 10^–5 and 10^–4 W/cm² at 2 and 3.4 μm wavelengths, respectively.