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

A novel near-infrared emitting Ga2O3: Ni2+ phosphor was prepared, and its emission characteristics were improved through melting aid and charge balance. Under 410 nm excitation, the Ga2O3: Ni2+ 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 Ga3+ and Ni2+ was eliminated through melting assistance and charge compensation. The results show that the emission intensity of Ga1.97O3: 0.015Ni2+, 0.015Ge4+ phosphor (with added flux H3BO3) is 10 times higher than that of Ga1.985O3: 0.015Ni2+ sample. Its quantum yield is as high as 31.2 %, significantly higher than the reported Ni2+ 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 Ga2O3: Ni2+, Ge4+-H3BO3 phosphor in composition analysis and detection.