Enhanced near-infrared II and III emission in Ga2O3: Ni2+ phosphor via charge compensation for NIR spectroscopy application

A novel near-infrared emitting Ga 2 O 3 : Ni 2+ phosphor was prepared, and its emission characteristics were improved through melting aid and charge balance. Under 410 nm excitation, the Ga 2 O 3 : Ni 2+ phosphor exhibits broadband near-infrared emission in the second region, with a peak at 1455 nm and a half maximum width of up to 300 nm. At the same time, the crystallinity of the sample was improved and the charge imbalance during substitution between Ga 3+ and Ni 2+ was eliminated through melting assistance and charge compensation. The results show that the emission intensity of Ga 1.97 O 3 : 0.015Ni 2+ , 0.015Ge 4+ phosphor (with added flux H 3 BO 3 ) is 10 times higher than that of Ga 1.985 O 3 : 0.015Ni 2+ sample. Its quantum yield is as high as 31.2 %, significantly higher than the reported Ni 2+ ion doped phosphors. According to the distinct absorptions of C–H, O–H as well as N–H bonds in the shortwave near-infrared range, samples of ethanol, n-hexanol, water and ammonia demonstrated different absorption peaks under the penetration of the constructed phosphor conversion light-emitting diode, which proved the potential application of Ga 2 O 3 : Ni 2+ , Ge 4+ -H 3 BO 3 phosphor in composition analysis and detection.