“Active Pixel Sensor Matrix Based on Monolayer MoS₂ Phototransistor Array”, Akhil Dodda, Darsith Jayachandran, Andrew Pannone, Nicholas Trainor, Sergei P. Stepanoff, Megan A. Steves, Shiva Subbulakshmi Radhakrishnan, Saiphaneendra Bachu, Claudio W. Ordonez, Jeffrey R. Shallenberger, Joan M. Redwing, Kenneth L. Knappenberger, Douglas E. Wolfe, Saptarshi Das2022-11-17 (tech)⁠:

[media] In-sensor processing, which can reduce the energy and hardware burden for many machine vision applications, is currently lacking in state-of-the-art active pixel sensor (APS) technology. Photosensitive and semiconducting two-dimensional (2D) materials can bridge this technology gap by integrating image capture (sense) and image processing (compute) capabilities in a single device.

Here, we introduce a 2D APS technology based on a monolayer MoS₂ phototransistor array, where each pixel uses a single programmable phototransistor, leading to a substantial reduction in footprint (900 pixels in ~0.09 cm²) and energy consumption (100s of femtojoules per pixel).

By exploiting gate-tunable persistent photoconductivity, we achieve a responsivity of ~3.6 × 10⁷ A W⁻¹, specific detectivity of ~5.6 × 10¹³ Jones, spectral uniformity, a high dynamic range of ~80 dB and in-sensor de-noising capabilities.

Further, we demonstrate near-ideal yield and uniformity in photoresponse across the 2D APS array.