Pr^(3+)掺杂Ge-Ga-S-KCl硫卤玻璃的近红外发光研究

Near infrared photoluminescence of Ge-Ga-S-KCl glasses doped with Pr^(3+) ions

采用熔融淬冷法制备掺Pr3+(0.1%,0.3%,0.5%,0.7%)(按物质的量计算百分数,下同)的0.64GeS2-0.16Ga2S3-0.2KCl硫卤玻璃.测试玻璃的光学吸收谱和光致发光谱,在红外吸收谱中有4个明显的吸收峰,分别是Pr3+的基态3H4向3F4,3F3,3F2和3H6激发态跃迁引起的吸收.近红外区的3个发光峰,分别对应1D2→1G4(~1 390 nm),3F4→3H4(~1 430 nm)和3F3→3H4(~1 480 nm)的跃迁.0.5l%PrCl3掺杂时该组分玻璃的发光强度最高,而且吸收峰和发光峰峰值位置比相应的硫系玻璃有蓝移.分析表明:吸收峰和发光峰的蓝移是由于硫卤玻璃的离子键性比相应的硫系玻璃的离子键性强,导致Pr3+的相应能级间隔增大.

Chalcohalide bulk glasses in the 0.64GeS2-0.16Ga2S3-0.2KCl system doped with PrCl3（0.1%,0.3%,0.5%,0.7%） were prepared by the classical melt-quenching technique.All samples have been measured by near and mid-infrared absorption spectra and low-temperature photoluminescence（PL） spectra.Four main absorption peaks（-at 1 426 nm,1 524 nm,1 922 nm,2 240 nm,respectively） were observed.They are assigned to the optical transitions from the ground state,3H4,to excited states of 3F4,3F3,3F2 and 3H6,respectively,of Pr^3＋ ions.Three near infrared PL bands were observed,which were ascribed to 1D2→1G4（-1 390 nm）,3F4→3H4（-1 430 nm） and 3F3→3H4（-1 480 nm） transitions,respectively.PL spectra results showed that 0.5% was the optimum PrCl3-doping concentration in the studied chalcohalide glasses.Both absorption peaks and PL peaks shifted to shorter wavelength（blue shift） compared with other Pr3＋-doped chalcogenide glasses.The blue shifts were due to weaker covalent bands characteristic of the studied chalcohalide glasses,which resulted in the increase of energy levels of the Pr^3＋ ions.