Abstract
Various large-area growth methods for two-dimensional transition metal dichalcogenides have been developed recently for future electronic and photonic applications. However, they have not yet been employed for synthesizing active pixel image sensors. Here, we report on an active pixel image sensor array with a bilayer MoS2 film prepared via a two-step large-area growth method. The active pixel of image sensor is composed of 2D MoS2 switching transistors and 2D MoS2 phototransistors. The maximum photoresponsivity (Rph) of the bilayer MoS2 phototransistors in an 8 × 8 active pixel image sensor array is statistically measured as high as 119.16 A W−1. With the aid of computational modeling, we find that the main mechanism for the high Rph of the bilayer MoS2 phototransistor is a photo-gating effect by the holes trapped at subgap states. The image-sensing characteristics of the bilayer MoS2 active pixel image sensor array are successfully investigated using light stencil projection.
Highlights
Various large-area growth methods for two-dimensional transition metal dichalcogenides have been developed recently for future electronic and photonic applications
The phototransistor was integrated into the pixel as a photodetector instead of a photodiode, which is typically used in active pixel image sensors, resulting in a higher photoresponsivity and signal-to-noise ratio (SNR)
The main mechanism for the high remarkably high photoresponsivity (Rph) of the bilayer MoS2 phototransistor is PG effect by the holes trapped at subgap states[33,52,53,54,55]
Summary
Various large-area growth methods for two-dimensional transition metal dichalcogenides have been developed recently for future electronic and photonic applications They have not yet been employed for synthesizing active pixel image sensors. Large-scale growth methods for TMDs have been reported, but they have not yet been employed to synthesize active pixel image sensors, which are integrated circuits consisting of photodetectors and active transistors that can detect the incident image light and convert it into digital image signals[26,27,28]. The simulations highlight the correlation between threshold voltage (Vth) shift and high Rph when including subgap states near the valence band edge Both the 64 switching transistors and the 64 phototransistors based on homogeneous semiconductor (i.e., bilayer MoS2) in the 8 × 8 active pixel array are systematically investigated. The proposed active pixel image sensor array can potentially be used for future image-sensing applications, such as ultra-thin image sensors, transparent image sensors, artificial-intelligence photosensors, and selective light-detecting imagers[29,30,31,32]
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
