Origin of visible luminescence in hydrogenated amorphous silicon nitride

We present a detailed investigation on the origin of the room-temperature visible luminescence in hydrogenated amorphous silicon nitride films. In combination with Raman spectroscopy and high resolution transmission electron microscopy, we demonstrate clearly that the red light emission originates from amorphous silicon quantum dots. On the basis of the redshift of peak position, narrowing of bandwidth, and temperature quenching of luminescence, we attribute the green emission to the bandtail recombination of carriers. In addition, the blue luminescence is assigned to the silicon-related defects according to the analysis for the gap states in silicon nitride. (c) 2007 American Institute of Physics.