Photoluminescence at 1540 nm from erbium-doped amorphous silicon carbide films

Abstract

Room-temperature photoluminescence (PL) was observed at 1540 nm in erbium-implanted amorphous silicon carbide (a-SiC:Er) films grown by thermal chemical vapor deposition at 800 °C. The PL spectra of the a-SiC:Er samples did not exhibit any defect-generated luminescence, with the PL intensity at 1540 nm dropping only by a factor of 3.6 as the sample temperature was increased from 14 K to room temperature. Time-resolved PL measurements showed that the Er3+ luminescence lifetime of approximately 0.6 ms was nearly independent of sample temperature. In addition, luminescence quenching was observed as implanted Er dose exceeded 7 × 1015 ions/cm2. It is suggested that the lower density of Si and C vacancies in the stoichiometric a-SiC:Er, as compared to its non-stoichiometric a-Si1-xCx counterpart, along with the incorporation of a higher Er dopant concentration, can effectively quench defect-produced luminescence and lead to a significant improvement in PL performance. These properties indicate that stoichiometric a-SiC is potentially a viable candidate for optoelectronic devices operating in the 1540 nm region.