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

Abstract

This study offers the first systematic exploration on the amorphous tellurium–selenium alloy photodetectors. Specifically, wafer‐scale Te0.65Se0.35 alloy nanofilms (up to 2 inches in diameter) have been successfully synthesized by exploiting pulsed‐laser deposition, which exhibit good uniformity. Notably, the alloyed Te0.65Se0.35 nanofilms have demonstrated an impressive Hall mobility of 20.5 cm2 V⁻1 s⁻1. The corresponding Te0.65Se0.35 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 × 109 Jones, respectively. By employing the Te0.65Se0.35 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 Te0.65Se0.35 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.