Effects of hydrogen plasma treatment on the 1.54 μm luminescence of erbium-doped porous silicon

Well resolved, sharp photoluminescence (PL) peaks of Er³⁺ (4f¹¹) ions at ∼1.54 μm are obtained from Er-doped porous silicon (PS:Er) on which a hydrogen plasma treatment is carried out after electrochemical incorporation of Er³⁺ions into porous silicon. The full width at half maximum (FWHM) of the 1.538 μm main peak at 20 K is less than 1 nm, which is much smaller than that obtained from PS:Er samples annealed in a H₂ or O₂ flow (FWHM 7-10 nm), and is comparable to that of Er-doped crystalline silicon. The thermal quenching of the PL intensity is, however, relatively small, the PL intensity decreasing only by a factor of 10 from 20 to 300 K.