The researchers tested the photovoltaic performance of the device under 1 sun of illumination with a solar simulator and measured its quantum efficiency.

Under laboratory conditions, the COFs demonstrate a quantum efficiency of 17.5 per cent under visible light at 420 nm in batch reactors.

Subsequent optical experiments revealed that the blue- and green-emitting supramolecular ink compounds exhibit what scientists call near-unity quantum efficiency.

PHOLEDs have nearly 100% internal quantum efficiency, meaning all of the electricity entering the device is used to create light.

But when nature — say, a spinach leaf, piece of seaweed or bacterium — converts solar power into usable energy via photosynthesis, it does so with a quantum efficiency of one.