Color-Filter-Free Image Sensor Using CsPbBr₃ Quantum-Dot-Based Tamm Plasmon Photodetector for Photonic Synapse Facial Recognition

This study demonstrates that optical absorption of the CsPbBr₃ quantum dots can be significantly enhanced through monolithic integration with the Tamm plasmon (TP) structure. This integration enables the resulting TP photodetector to achieve a higher photocurrent and a more linear power dependence compared to the reference device with a nonresonant configuration. The enhancement is confined to the designed resonant energy, while photons with off-resonance energies are fully reflected, making the TP photodetector an ideal candidate for compact and efficient image sensors, eliminating the need for additional filters or bulky microlenses for color discrimination or photon collection. Furthermore, the photocurrent generated by the TP photodetector can be regulated by varying light pulse stimulations, enabling it to mimic the synaptic dynamics of the human brain. By integrating the functions of perception, processing, and memorization of visual images, its potential for facial recognition through simulation based on a 64 × 64 array of TP photodetectors under the artificial neural network-based weight-update expectation thresholding model is demonstrated. These findings mark a significant step forward in utilizing all-inorganic perovskite materials for compact, color-filter-free image sensors and open new avenues for photonic neural computations on a single platform.