Shortcomings in efficiency modelling of hot carrier solar cells: Considering device concepts and hot carrier absorber materials from a practical viewpoint

The hot carrier solar cell (HCSC) thermodynamic model was introduced with a very high conversion efficiency eta, showing their potential for solar energy conversion. Although understanding HCSC physics and operation in detail from experimental data is crucial, no dedicated HCSC device has been processed. We evaluate eta models in view of realistic features and parameters. Phonon polaritons and elastic electron-electron scattering are vital non-equilibrium phenomena which have a strong impact on eta, yet have not been included properly in HCSC modelling. Starting with its original concept, we evaluate several HCSC types from a practical viewpoint. Boron antimonide (BSb) is a hot carrier absorber (HCA) material with excellent phonon ((h) over bar omega) dispersion and electronic properties. It has a strong hot (h) over bar omega bottleneck as evident from electronic and (h) over bar omega dispersions obtained by density functional theory (DFT) calculations, corroborated by measured strong photon absorption near its indirect electronic band gap. (C) 2014 The Japan Society of Applied Physics