Influence of Yb 3+ /Ho 3+ codoping on optical and thermal properties of TeO 2 -ZnO glass.

This paper reports the effect of incorporation of Yb 3+ ions on the frequency downconversion luminescence and thermal properties of triply ionised Ho 3+ doped zinc tellurite (TZ) glasses. The photoluminescence spectra of both the Ho 3+ /Yb 3+ doped and codoped glasses have been recorded and observed a green emission band corresponding to the 5 F 4 , 5 S 2 → 5 I 8 (∼550 nm) transition upon various excitations. In the downconversion (DC) emission process, the back energy transfer (BET) mechanism from Ho 3+ ions to Yb 3+ ions has also been explored. The colour emitted in the downconversion process is found to be non-tunable at different excitations. Thus, the Ho 3+ :TZ glass can be utilised for non-colour tunable optical devices under various UV excitations. Also the glass transition (T g ) and crystallisation (T c ) temperatures have been measured for both the doped and codoped glasses and found to be increased in the codoped glass. The singly Ho 3+ ions doped TZ glass shows better optical downconversion and glass forming ability.