Amorphous Tellurium–Selenium Alloy: A Promising Candidate Material Toward Broadband Optoelectronics

This study offers the first systematic exploration on the amorphous tellurium–selenium alloy photodetectors. Specifically, wafer‐scale Te 0.65 Se 0.35 alloy nanofilms (up to 2 inches in diameter) have been successfully synthesized by exploiting pulsed‐laser deposition, which exhibit good uniformity. Notably, the alloyed Te 0.65 Se 0.35 nanofilms have demonstrated an impressive Hall mobility of 20.5 cm 2 V⁻ 1 s⁻ 1 . The corresponding Te 0.65 Se 0.35 alloy photodetectors have exhibited a broadband photoresponse from 405 to 1550 nm. Under 635 nm illumination, the devices have achieved high responsivity, external quantum efficiency, and detectivity values of 7.35 A W −1 , 1440%, and 1.32 × 10 9 Jones, respectively. By employing the Te 0.65 Se 0.35 alloy devices as the pivotal sensing components, proof‐of‐concept broadband optoelectronic imaging applications surpassing human optesthesia and optical communication applications in the low loss window have been realized. Moreover, the preparation of the arrayed devices has been successfully validated, which exhibit qualified device‐to‐device variation, laying a solid foundation for practical production. In the end, flexible Te 0.65 Se 0.35 photodetectors with excellent bendability and anti‐impact capability have been realized. On the whole, this study contributes to the enrichment of the optoelectronic material family, potentially broadening the horizons of future optoelectronic applications.