A plot of the efficiency of a step (η) against wavelength or photon energy.
See: action spectrum, conversion spectrum
See also: spectral effectiveness
Source:
PAC, 1996, 68, 2223. 'Glossary of terms used in photochemistry (IUPAC Recommendations 1996)' on page 2238 (https://doi.org/10.1351/pac199668122223)