Subband Light Emission from Phosphorous-Doped Amorphous Si/SiO₂ Multilayers at Room Temperature

Phosphorous-doped hydrogenated amorphous Si/SiO₂ multilayer structures are fabricated in a plasma enhanced chemical vapor deposition system. The microstructural and luminescence properties of the samples are characterized after annealing at various temperatures. Under the onset crystallization temperature 800–900 °C, a strong subband infrared light emission in the range 1.1–1.8 μm is observed at room temperature instead of the usually observed visible light emission. This subband infrared emission is gradually enhanced with the increase of phosphorus doping concentration, which can be ascribed to the increase of the luminescent defect states promoted by the doped phosphorous atoms.