Processing for highly emissive CZ-silicon by depositing stressed sol-gel films

Enhanced band-gap emission from Czochralski silicon substrates of up to ~100 times is reported. This was achieved by processing for a stressed interface resulting from baked and annealed silica films prepared by sol-gel processes. The active dopants include but are not limited to erbium and are prepared with tetraethylorthosilicate (TEOS) while forming the active precursors using oxide and nitrate forms of the rare earth. In addition, annealed films produce infrared emission in the 1.5-μm band from erbium ions in the film. Steady-state photoluminescence studies indicate that a strong correlation of the intensity of the emission at the band gap to the stress formed at the interface and is a direct function of the annealing temperature of the silica films, independent from the known erbium 4f emission bands.