Terahertz In-Sensor Computing Utilizing Photothermoelectric Thin Films

Terahertz (THz) detection is pivotal for biomedical diagnostics and security screening, enabled by its non-ionizing nature and characteristic "fingerprint" spectra. However, weak THz-matter interactions, energy-intensive processing, and complex hardware integration hinder its practical use. To this aim, a layered bismuth selenide (Bi₂Se₃)-based THz detection array is fabricated via low-temperature pulse irradiation synthesis (PIS), exhibiting a tunable thermally coupled bidirectional response. The intrinsic photothermoelectric (PTE) effect enables adaptive in-sensor THz signal processing, achieving 200 V W^-1 responsivity and <5 ms response time at 0.3 THz in a self-powered mode. Integrated in-sensor computing enhances accuracy through real-time noise suppression, edge detection, and feature extraction. The array also demonstrates high imaging performance, with a >90% recall rate for concealed object detection. This work provides a scalable, high-precision THz sensing platform with transformative potential for biomedical and security applications.