What is the comparison to modern camera sensors nowadays? Can they detect single photons?
There's also SPADs "single photon avalanche diodes". These are sort of like a geiger counter for light, i.e. a single interacting photon triggers an impulse that can be counted or timed. These are very commonly used for time-of-flight sensors.
For detecting single photons, you need really high in-sensor amplification. Options include SPADs or photomultipliers if you don't need an image, or image intensifier tubes (used in night vision) if you do need an image. Semiconductor cameras that use IIT-like operational principles are in development now, undergoing testing for next-gen (digital) night vision.