Highly sensitive active pixel image sensor array driven by large-area bilayer MoS 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 MoS film prepared via a two-step large-area growth method. The active pixel of image sensor is composed of 2D MoS switching transistors and 2D MoS phototransistors. The maximum photoresponsivity (R) of the bilayer MoS phototransistors in an 8 × 8 active pixel image sensor array is statistically measured as high as 119.16 A W. With the aid of computational modeling, we find that the main mechanism for the high R of the bilayer MoS phototransistor is a photo-gating effect by the holes trapped at subgap states. The image-sensing characteristics of the bilayer MoS active pixel image sensor array are successfully investigated using light stencil projection.