Lower non-radiative transition probability in Er3+-doped bromide-modified sulfide glasses

Abstract New sulfo-bromide glasses of the (60− x )GaS 3/2 · x GaBr 3 ·10GeS 2 ·30LnS 3/2 composition (Ln=La and Er; x =0, 5, 10, 15 and 20) were prepared. Their thermal and optical properties were measured. The bromide-modified glasses exhibited more prominent thermal stability than sulfide glasses of the 60GaS 3/2 ·10GeS 2 ·30LnS 3/2 composition (GGLS). As bromides were added to the GGLS glass, the color of the glass changes from red–orange for GGLS glass to pale yellow for bromide-modified sulfide glasses, and consequently the band gaps shifted to shorter wavelengths. As a result, the Er 3+ green up-conversion luminescence intensities at around 525 and 550 nm in the bromide-modified glasses became stronger compared with those in pure GGLS glasses.