Selective sensing in perovskite-based image sensors

Broadband image sensors are yet to produce the required color constancy for the emerging applications in artificial intelligence and neural network. In this work, narrowband absorption across the visible range is discussed and image sensors with Full Width at Half Maximum of less than 200 nm are realized. The active layer in these image sensors comprises the light absorbing perovskite structures, ABX3, combined with a macromolecule, methylene blue. The variations in the X site of the perovskite sets the limit for the lower frequency of the absorption bandwidth whereas the upper limit is set due to the presence of the methylene blue. This synthetic dye further enhances the crystallinity of the structure and, consequently, lowers the leakage current by two orders of magnitude. A vertically integrated perovskite-silicon image sensor is then realized. This narrowband absorbing hybrid concept may be easily connected to image sensing circuitry. This compatibility in fabrication directly results in reductions of architectural complexity and cost. The detectivity of the proof of concept image sensors is E11 cmHz1/2W−1. This value is considered well above average among the best performing commercialized image sensors.