«Loss mitigation in plasmonic solar cells: aluminium nanoparticles for broadband photocurrent enhancements in GaAs photodiodes» is published by N P Hylton et al in Nature Scientific Reports doi: 10.1038 / srep02874
We measure incident photon - to - current efficiency (IPCE) to get a wavelength - dependent conversion efficiency that can be integrated over a reference spectrum (AM1.5 G) to corroborate the photocurrents obtained under broadband illumination.