Surface engineering of highly ordered Bi2S3 film with open channels toward high‐performance broadband photodetection

Abstract

Abstract The highly ordered film assembled by regularly 1D nanostructures has potential prospects in electronic, photoelectronic and other fields because of its excellent light‐trapping effect and electronic transport property. However, the controlled growth of highly ordered film remains a great challenge. Herein, large‐area and highly ordered Bi2S3 film is synthesized on fluorophlogopite mica substrate by chemical vapor deposition method. The Bi2S3 film features hollowed‐out crosslinked network structure, assembled by 1D nanobelts that regularly distribute in three orientations, which agrees well with the first principles calculations. Based on the as‐grown Bi2S3 film, the broadband photodetector with a response range from 365 to 940 nm is fabricated, exhibiting a maximum responsivity up to 98.51 mA W–1, specific detectivity of 2.03 × 1010 Jones and fast response time of 35.19 ms. The stable instantaneous on/off behavior for 500 cycles and reliable photoresponse characteristics of the Bi2S3 photodetector after storage in air for 6 months confirm its excellent long‐term stability and air stability. Significantly, as sensing pixel and signal receiving terminal, the device successfully achieves high‐resolution imaging of characters of “H”, “I” and “T”, and secure transmission of confidential information. This work shows a great potential of the large‐area and highly ordered Bi2S3 film toward the development of future multiple functional photoelectronic applications.

Keywords

• broadband photodetection
• encrypted communication
• highly ordered Bi2S3 film
• imaging
• open channel