In the present work, strong room-temperature photoluminescence (PL) at 1540 nm is reported from erbium-implanted and post-annealed amorphous silicon carbide (a-SiC:Er) films. The stoichiometric SiC films were grown by thermal chemical vapor deposition (TCVD) at 800°C, and then implanted to Er fluence of 3×1015 ions/cm2 using 380 keV implantation energy. Post-implantation annealing was carried out at the temperature range of 550°C to 1350°C in argon (Ar) ambient. The resulting SiC films were characterized by Auger electron spectroscopy (AES), Rutherford backscattering (RBS), Fourier transform infrared spectroscopy (FTIR), nuclear reaction analysis (NRA), x-ray diffraction (XRD), and high-resolution transmission electron microscope (HRTEM). Clear PL behavior was seen from the annealed a-SiC:Er samples, even at room temperature, with PL intensity reaching a maximum for samples annealed at 900°C.
Additional studies of thermal quenching of Er luminescence from a-SiC:Er samples annealed at 900°C indicated that as the sample temperature increased from 14K to room temperature, the luminescence intensity at 1540 nm dropped by a factor of ∼ 3.6. Moreover, the PL spectra of the a-SiC:Er samples did not exhibit any defect-generated luminescence. 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 diminish defect-produced luminescence and lead to a significant improvement in PL performance.
These properties suggest that stoichiometric a-SiC:Er may be a good candidate for producing optoelectronic devices operating in the 1540 nm region.