• A 64×64 MWIR snapshot photodetector array was fabricated using a room-temperature BP ink deposition technique, achieving low oxidation loss of 1.12%.
• Gradient centrifugation optimized BP nanosheet size and thickness, enhancing charge carrier transport and device performance.
• The BP ink film array exhibited a photoresponsivity of 4.52 mA/W in the MWIR range with pixel non-uniformity as low as 10.1%.
• This work provides a scalable route for large-area, uniform BP-based MWIR imaging arrays, overcoming limitations of conventional epitaxial methods.