Investigation of PL properties of C-doped SiO2/Si samples after high energy Pb ion irradiation

摘要

Amorphous SiO2 thin films with about 400-500 nm in thickness were thermally grown on single crystalline silicon.These SiO2/Si samples were firstly implanted at room temperature (RT) with 100 keV carbon ions to 2.0 × 1017,5.0 × 1017 or 1.2 × 1018 ions/cm2,then irradiated at RT by 853 MeV Pb ions to 5.0 × 1011,1.0 × 1012,2.0 × 1012 or 5.0 × 1012 ions/cm2,respectively.The variation of photoluminescence (PL) properties of these samples was analyzed at RT using a fluorescent spectroscopy.The obtained results showed that Pb-ion irradiations led to significant changes of the PL properties of the carbon ion implanted SiO2 films.For examples,5.0 × 1012 Pb-ions/cm2 irradiation produced huge blue and green light-emitters in 2.0 × 1017 C-ions/cm2 implanted samples,which resulted in the appearance of two intense PL peaks at about 2.64 and 2.19 eV.For 5.0 × 1017 carbon-ions/cm2 implanted samples,2.0 × 1012 Pb-ions/cm2 irradiation could induce the formation of a strong and wide violet band at about 2.90 eV,whereas 5.0 × 1012 Pb-ions/cm2 irradiation could create double peaks of light emissions at about 2.23 and 2.83 eV.There is no observable PL peak in the 1.2 × 1018 carbon-ions/cm2 implanted samples whether it was irradiated with Pb ions or not.All these results implied that special light emitters could be achieved by using proper ion implantation and irradiation conditions,and it will be very useful for the synthesis of new type of SiO2-based light-emission materials.