Centimeter‐Scale Au 0.58 Te 0.42 for Ultra‐Broadband Photonic Detection and Spectral Imaging

Broadband photodetectors spanning from UV to terahertz wavelengths are crucial for applications in medical diagnostics, industrial inspection, and advanced imaging. However, scalable fabrication of suitable materials remains a major bottleneck. Here, the molecular beam epitaxy growth of centimeter‐scale metallic crystalline Au 0.58 Te 0.42 film is reported—marking an important advancement in the scalable synthesis of metal tellurides. Exploiting its intrinsic broadband free‐electron absorption, ultra‐broadband photonic detection from 325 nm to 119 µm, with strong THz coupling that circumvents the need for complex antenna structures is demonstrated. The detector achieves a room‐temperature responsivity up to 136 mA W −1 (1.34 × 10 −3 mA W −1 ) and a noise‐equivalent power of 14.7 nW Hz −0.5 (9.5 × 10 4 nW Hz −0.5 ) at 2.52 THz, operating effectively in biased (self‐powered) mode. A response time of 320 ms is also achieved. Moreover, broadband spectral imaging of multilayered targets is realized, underscoring the potential for high‐contrast, multi‐spectral diagnostics. This work highlights metal tellurides as a scalable platform for high‐performance broadband photonic detection and imaging, offering new opportunities for next‐generation THz optoelectronics.