The non-radiative efficiency in hydrogenated amorphous silicon

The non-radiative efficiencyηnr has been directly measured in hydrogenated amorphous silicon using photo-pyroelectric spectroscopy, for photon energies ranging from 1·5 to 2·2 eV at room temperature. The non-radiative efficiency is fairly constant for above-bandgap illumination, but displays a sharp minimum for photon energies near the bandgap energy.ηnr increases with sub-bandgap illumination, saturating at a value roughly one half as large as its high-energy value.