  Image sensors with internal computing capability enable in-sensor computing
that can significantly reduce the communication latency and power consumption
for machine vision in distributed systems and robotics. Two-dimensional
semiconductors are uniquely advantageous in realizing such intelligent
visionary sensors because of their tunable electrical and optical properties
and amenability for heterogeneous integration. Here, we report a
multifunctional infrared image sensor based on an array of black phosphorous
programmable phototransistors (bP-PPT). By controlling the stored charges in
the gate dielectric layers electrically and optically, the bP-PPT's electrical
conductance and photoresponsivity can be locally or remotely programmed with
high precision to implement an in-sensor convolutional neural network (CNN).
The sensor array can receive optical images transmitted over a broad spectral
range in the infrared and perform inference computation to process and
recognize the images with 92% accuracy. The demonstrated multispectral infrared
imaging and in-sensor computing with the black phosphorous optoelectronic
sensor array can be scaled up to build a more complex visionary neural network,
which will find many promising applications for distributed and remote
multispectral sensing.
