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

Abstract

Despite the widespread interest in MoS 2 -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 MoS 2 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 MoS 2 film for photoimaging. Here, the film is constructed by spin-coating of the MoS 2 nanosheets, which are acquired via electrochemical intercalation and sonicationassisted exfoliation. By precisely controlling this process, semiconducting fewlayered MoS 2 nanosheets with pure phase can be obtained. High-performance photodetectors have been achieved for the TFSI-treated MoS 2 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 liquidexfoliated MoS 2 nanosheets. Furthermore, a fully integrated photoimaging device with a crossing structure and an effective pixel density of 460/cm 2 has been fabricated based on the MoS 2 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.

Inkjet‐Printed, Large‐Area, Flexible Photodetector Array Based on Electrochemical Exfoliated MoS2 Film for Photoimaging

“…However, it is hard to control the location and distribution of the MoS 2 nanosheets during the spin coating process, which seriously limits the application of the electrochemical exfoliated nanosheets. Different from the spin coating, [ 23 ] inkjet printing provides a more uniform deposition surface in small scope. As a typical additive manufacturing, inkjet printing demonstrates great promise in fabricating electronic devices.…”

Polarization-Sensitive, Self-Powered, and Broadband Semimetal MoTe2/MoS2 van der Waals Heterojunction for Photodetection and Imaging

“…Figure c presents the responsivity ( R ) and specific detectivity ( D *) as a function of light power density under 915 nm at 0 V. Here, R is defined as photocurrent generated from per unit incident power on the effective area and calculated by the following formula: , italicR = I p h P i n italicA d where I ph is the current under illumination ( I illu ) subtracts dark current ( I dark ), P in is incident power density and A d is effective area. D * represents the ability of the photodetector to detect weak light signals and can be obtained as D * = A d B normalN normalE normalP normalN normalE normalP = i n 2 R where A d , B , NEP, i n , and R are the effective area, noise bandwidth, noise equivalent power (NEP), total noise current, and responsivity of the photodetector.…”

“…Figure 3c presents the responsivity (R) and specific detectivity (D*) as a function of light power density under 915 nm at 0 V. Here, R is defined as photocurrent generated from per unit incident power on the effective area and calculated by the following formula: 48,49 where A d , B, NEP, i n , and R are the effective area, noise bandwidth, noise equivalent power (NEP), total noise current, and responsivity of the photodetector. The total noise current can be obtained from the frequency-dependent noise spectral density at 1 Hz bandwidth.…”

Quantum enhanced efficiency and spectral performance of paper-based flexible photodetectors functionalized with two dimensional materials

“…After that, exfoliated MoS 2 flakes are mixed in a suitable solvent to create a spin-coatable solution which was then placed onto the substrate. The spin-coated film served as the active layer of the PD array, responsible for light absorption and electron-hole generation, allowing efficient light absorption and facilitated high photoresponsivity [109].…”