title: Efficient silicon light-emitting diodes.
abstract: Considerable effort is being expended on the development of efficient silicon light-emitting devices compatible with silicon-based integrated circuit technology. Although several approaches are being explored, all presently suffer from low emission efficiencies, with values in the 0.01-0.1% range regarded as high. Here we report a large increase in silicon light-emitting diode power conversion efficiency to values above 1% near room temperature-close to the values of representative direct bandgap emitters of a little more than a decade ago. Our devices are based on normally weak one- and two-phonon assisted sub-bandgap light-emission processes. Their design takes advantage of the reciprocity between light absorption and emission by maximizing absorption at relevant sub-bandgap wavelengths while reducing the scope for parasitic non-radiative recombination within the diode. Each feature individually is shown to improve the emission efficiency by a factor of ten, which accounts for the improvement by a factor of one hundred on the efficiency of baseline devices.
authors.affiliation: Centre for Third Generation Photovoltaics, University of New South Wales, Sydney, New South Wales 2052, Australia. m.green@unsw.edu.au
authors.forename: M A
authors.initials: MA
authors.lastname: Green
authors.forename: J
authors.initials: J
authors.lastname: Zhao
authors.forename: A
authors.initials: A
authors.lastname: Wang
authors.forename: P J
authors.initials: PJ
authors.lastname: Reece
authors.forename: M
authors.initials: M
authors.lastname: Gal