Saeed, Sabade Weerd, ChrisStallinga, PeterSpoor, Frank C. M.Houtepen, Arjan J.Siebbeles, Laurens D. A.Gregorkiewicz, Tom2018-12-072018-12-072015-022047-7538http://hdl.handle.net/10400.1/11277Carrier multiplication is demonstrated in a solid-state dispersion of germanium nanocrystals in a silicon-dioxide matrix. This is performed by comparing ultrafast photo-induced absorption transients at different pump photon energies below and above the threshold energy for this process. The average germanium nanocrystal size is approximately 5-6 nm, as inferred from photoluminescence and Raman spectra. A carrier multiplication efficiency of approximately 190% is measured for photo-excitation at 2.8 times the optical bandgap of germanium nanocrystals, deduced from their photoluminescence spectra.engMultiple exciton generationSilicon nanocrystalsAuger recombinationSolar-cellsQuantum confinementImpact ionizationPbse nanorodsEfficiencyFilmsPhotoluminescencejournal article10.1038/lsa.2015.24