Maximizing light emission from silicon nanocrystals – The role of hydrogen

Time-resolved photoluminescence measurements are undertaken to determine the passivation kinetics of luminescence-quenching defects during isothermal and isochronal annealing in molecular and atomic hydrogen. The latter employs an alneal process in which atomic hydrogen is generated by reactions between a deposited Al layer and H2O or –OH radicals in the SiO2. Passivation and desorption kinetics are shown to be consistent with the existence of two classes of non-radiative defects: one that reacts with either atomic or molecular hydrogen, and the other that reacts only with atomic hydrogen.