Enhance the luminescence properties of Ca14Al10Zn6O35:Ti4+ phosphor via cation vacancies engineering of Ca2+ and Zn2+

Ti⁴⁺-activated zinc calcium aluminate phosphors, owing to their excellent luminescence properties, nontoxicity, environment friendliness and low price, have a certain prospect in the field of plant cultivation. In this study, we have successfully synthesized a series of Ca_14-yAl_10-xZn_6-zO₃₅:xTi⁴⁺ (CAZO:Ti⁴⁺) phosphors through a high-temperature solid-state method. Furthermore, the emission spectrum of CAZO:Ti⁴⁺ located in bluish violet-emitting band, and has an emission peak at 378?nm upon the excitation of 268?nm due to the charge transfer of Ti⁴⁺-O^2-. Moreover, the luminescence intensity of as-synthetized phosphors can be improved by cation vacancies engineering to compensate for charge unbalance. Especially, the luminescence intensity could be further improved when the Ca²⁺ vacancy is 0.35?mol or the Zn²⁺ vacancy is 0.275?mol. Furthermore, the X-ray powder diffraction (XRD) analysis and crystal structure are checked and confirmed that the synthesized material is pure phase. The concentration quenching mechanism, FT-IR spectra, UV–vis absorption properties, lifetimes and electron transition process of Ca_14-yAl_10-xZn_6-zO₃₅: xTi⁴⁺ were discussed in detail. From the above, the phosphor has a potential application for plant growth field due to its broad bluish violet emission.