Visible luminescence from hydrogenated amorphous silicon modified by   femtosecond laser radiation
  Visible luminescence is observed from the composite of SiO2 with embedded silicon nanocrystallites produced by femtosecond laser irradiation of hydrogenated amorphous silicon (a-Si:H) film in air. The photoluminescence originates from the defect states at the interface between silicon crystallites and SiO2 matrix. The method could be used for fabrication of luminescent layers to increase energy conversion of a-Si:H solar cells. 
Andrey V. Emelyanov, Andrey G. Kazanskii, Mark V. Khenkin, Pavel A.   Forsh, Pavel K. Kashkarov, Mindaugas Gecevicius, Marty...
physics.optics cond-mat.mtrl-sci