Room Temperature Visible Photoluminescence from ThermallyAnnealed Hydrogenated Amorphous Silicon Films

A visible photoluminescence from a thermally annealed boron doped hydrogenated amorphous silicon (a-Si : H) film has been observed at room temperature. The wavelength at the peak of the photoluminescent spectra is about 600nm. The intensity of photoluminescence is dependent on the annealing temperature strongly and relative to the deposition technology parameters of the films, especially to the hydrogen dilution of the boron doped silane and the deposition rate of the films. There exists a quantum size effect of nanometer-scale porosity on the surface of the annealed a-Si: H film. The quantum-confined structures may form due to the evolution of hydrogen from the surface of the films during the annealing procedure. The density of the porosity is relative to the quantity of evolved hydrogen from the film and the evolution rate of the hydrogen.