Flexible Bi2Te3 photothermoelectric thin film detector with broadband response at room temperature

Broadband photodetection is paramount for various applications like imaging and sensing, thus garnering significant attention as a research hot spot in recent years. However, it is challenging to detect infrared light at room temperature due to itslow photon energy. Here, we demonstrate a Bi₂Te₃ photothermoelectric thin film photodetector fabricated using controllable and large-scale magnetron sputtering technology. The proposed device exhibits a sensitivity exceeding 9.72 mA/W and a specific detectivity of 4.52 × 10⁸ Jones under 10.37 μm infrared light illumination at room temperature. The satisfied photoresponse observed stems from an electron temperature gradient rather than electron–hole separation. Furthermore, the Bi₂Te₃ photodetector presents high performance with high airstability, broadband spectrum photodetection from visible to the mid-infrared range. This investigation paves a way for developing high-performance photodetectors leveraging topological insulator materials endowed with remarkable thermoelectric properties.