  We have demonstrated an up to seven-fold enhancement of photoluminescence
from silicon-rich silicon nitride film due to a single photonic crystal cavity.
The enhancement is partially attributed to the Purcell effect. Purcell factor
predicted by FDTD calculations is 32 for a linear three-defect cavity mode with
computed quality factor of 332 and mode volume of 0.785 cubic wavelengths.
Experimentally measured cavity quality (Q) factors vary in the range of 200 to
300, showing excellent agreement with calculations. The emission peak can be
tuned to any wavelength in the 600 to 800 nm range.
