Highly sensitive active pixel image sensor array driven by large-area bilayer MoS₂ transistor circuitry

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 (R_ph) 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 R_ph 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.