Engineering cation vacancies to improve the luminescence properties of Ca14Al10Zn6O35: Mn4+ phosphors for LED plant lamp

In the recent years, Mn4+-doped phosphors for indoor plant cultivation have received extensive concern owing to the far-red emission that can match well with the absorption spectra of plant pigments. Whereas, many Mn4+-doped phosphors still face some challenges such as poor light efficiency and low thermal stability. It is an effective way to resolve these problems via cation vacancies engineering. Herein, the Ca14-xAl10Zn6-yO35: Mn4+ phosphors are successfully synthesized by combustion method. The luminescence intensity of Ca14-xAl10Zn6-yO35: Mn4+ phosphor is enhanced through engineering Ca2+ and Zn2+ vacancies according to the charge compensation mechanism. The optimal content of each Ca2+ and Zn2+ vacancy is equal to be 0.3. Furthermore, the defect formation is accompanied with lattice distortion, which plays a vital role in driving the excited phonon traps to reduce the energy loss by non-radiation transitions. Therefore, the thermal stability of Ca14-xAl10Zn6-yO35: Mn4+ phosphor is also improved via engineering cation vacancies. In addition, the Ca14-xAl10Zn6-yO35: Mn4+ phosphors can be effectively excited by blue light and it exhibits far-red emission due to the Mn4+ spin-forbidden E-2 -> (4)A(2) transition. The results suggest that the Ca14-xAl10Zn6-yO35: Mn4+ phosphors can have a tremendous potential in indoor plant cultivation.