Materials that are efficient sources of light are usually efficient at light detection.

2D materials are single or multiple layers of single-atom thick elements or compound; These often exhibit properties that differ from that material in bulk.

A combination of single or multiple layers of 2D materials has been used to create Very efficient light sources.
However - when those layers have been less than perfectly aligned - there has been a fall off in their efficiency.

It looks like this has aspect (consistent input/output when not aligned) has now been solved:

[Length : 03:34] [Light detection mentioned at 02:29]

This could open up camera sensors that are more (frequency) selective / more efficient / lower noise.