Achieving Luminescence of SrGaInGeO:0.03Cr via [In] Substitution [Ga] and Its Application to NIR -LED in Non-Destructive Testing.

Cr-doped SrGaGeO:0.03Cr (SGGO:0.03Cr) phosphor was synthesized via a high-temperature solid-phase method. Considering the tunable structure of SGGO, Ga ions in the matrix were substituted with In ions at a certain concentration. The tuned phosphor produced a red-shifted emission spectrum, with its luminescence intensity at 423 K maintained at 63% of that at room temperature; moreover, the internal quantum efficiency increased to 65.60%, and the external quantum efficiency correspondingly increased to 21.94%. On this basis, SGIGO:0.03Cr was encapsulated into a -LED, which was applied in non-destructive testing (NDT) experiments, successfully realizing the recognition of water and anhydrous ethanol, proving its potential application in the field of NDT.