It suggests that the cells are more sensitive towards the V.U. end of the spectrum.
Actually, it depends on the type of solar cell. All of our power is solar generated. We use a special type of cell that has 3 layers. Although seemingly not as efficient during bright sunlight as some others, it makes it up by being much more efficient at reduced light, especially partially shaded. The particular brand is United Solar
Uni-solar web page here Most solar cells have very reduced output in shade. The Uni-Solar cells have three layers for various wavelengths of light. We live in a rv (caravan) and have been "off the grid" since '97.