High‐Performance Visible‐Light Photodetectors built on 2D‐Nanoplate‐Assembled Large‐Scale BiI3 Films

Abstract The growth of large‐scale films forms the cornerstone for future integrated photodetection applications of 2D materials. However, there is still an unwelcome trade‐off between the size of these films and the performances of devices fabricated using them. To deal with this issue, a possible scheme for film assembly is proposed using high‐quality nanolayers to achieve both outstanding device performance and large film area. Specifically, photodetectors are fabricated on nanostructured BiI 3 films (1 × 1 cm 2 ) assembled with interlaced, vertically grown 2D nanoplates. These devices inherent the excellent photodetecting capability of single‐BiI 3 ‐nanoplate‐based photodetectors, showing responsivity of up to 2.22 AW −1 , high speed photoresponse of 2 ms/5.3 ms for rise/decay times, and outstanding specific detectivity as high as 1.65 × 10 12 Jones. This suggest that this approach to preparing large‐scale 2D BiI 3 films holds potential for the realization of integrated high‐performance photosensing devices. Furthermore, it is anticipated that it can be to other 2D materials.