Amorphous silicon nitride microcavities

Abstract

Amorphous silicon nitride microcavities were fabricated by use of distributed Bragg reflectors. The distributed Bragg reflectors were fabricated with alternating layers of quarter-wavelength-thick hydrogenated amorphous silicon nitride and amorphous silicon oxide. The spectral peak of the bulk amorphous silicon nitride photoluminescence spectrum was chosen as the microcavity resonance wavelength. The amorphous silicon nitride microcavity enhances the photoluminescence amplitude and reduces the photoluminescence linewidth with respect to the bulk amorphous silicon nitride. This narrowing and enhancement of the photoluminescence can be understood by the redistribution of the density of optical modes owing to the presence of the microcavity. The microcavity narrowing and enhancement of luminescence in hydrogenated amorphous silicon nitride opens up a variety of possibilities for optoelectronic applications such as resonant-cavity-enhanced light-emitting diodes and color flat-panel displays.