Fully Integrated Photodetector Array Based on an Electrochemically Exfoliated, Atomically Thin MoS₂ Film for Photoimaging

Despite the widespread interest in MoS2-based photodetectors over the past few years, use of a high-performance photoimaging device remains a major challenge due to the low yield and poor quality of the MoS2 film. In this paper, we demonstrate a simple method to fabricate a high-performance fully integrated photodetector array based on a large-area atomically thin MoS2 film for photoimaging. Here, the film is constructed by spin-coating of the MoS2 nanosheets, which are acquired via electrochemical intercalation and sonication-assisted exfoliation. By precisely controlling this process, semiconducting few-layered MoS2 nanosheets with pure phase can be obtained. High-performance photodetectors have been achieved for the TFSI-treated MoS2 film, as the responsivity reaches 1080 A/W, and the response/recovery time improved to 56/62 ms with high stability during the repeated on/off test. The overall performance is much better than that of previously reported photodetectors based on liquid-exfoliated MoS2 nanosheets. Furthermore, a fully integrated photoimaging device with a crossing structure and an effective pixel density of 460/cm2 has been fabricated based on the MoS2 film, and shows great potential for shape imaging with cross-talk suppression. We believe this work provides an approach to exploit the photodetector and image sensor based on layered materials.