Study On The Upconversion White Luminescence Properties Of C12A7: Ho³⁺/Yb³⁺/Tm³⁺/Mn²⁺ Polycrystalline

12CaO7Al2O3(C12A7) was composed by Ca, O and Al elements. The calciumoxide and aluminum oxide that used to synthesis of C12A7were large reserves,inexpensive and no environmental pollution. C12A7has good electrical properties, Ifwe can achieve upconversion white luminescence in C12A7, it will haveoptoelectronic properties, which not only had important theoretical significance, butalso had a high use value.In this paper, Ho3+, Yb3+, Tm3+and Mn2+doped C12A7polycrystalline wereprepared by high temperature solid-state method, and the best synthesis conditionsthat sintering8h under1150℃was studied.A series of C12A7: Ho3+/Yb3+/Tm3+/Mn2+polycrystalline were prepared by hightemperature solid-state method. The XRD results showed that the rare earth ions andMn2+ions did not change the crystal structure of the matrix material. Theupconversion luminescence spectra showed that with the doped concentration ofMn2+ions increase, the upconversion luminescence intensity of red,green and blueemission all changed. In order to achieve upconversion white luminescence emissioneasily, the Mn2+ions doped concentration was0.6mol%.The doped concentration of Ho3+ions, Yb3+ions, and Tm3+ions was studied byorthogonal test. The influence trend of rare earth ions doped concentration onupconversion luminescence intensity of red, green and blue emission was obtained.The best scheme was selected, and the way to achieve upconversion whiteluminescence emission that increasing the doped concentration of Ho3+ions ordecreasing the doped concentration of Tm3+ions was obtained. The doped concentration of rare earth ions was adjusted on the basis oforthogonal test, C12A7:0.4mol%Ho3+/4mol%Yb3+/0.6mol%Tm3+/0.6mol%Mn2+polycrystalline sample was prepared. The CIE coordinates of the sample showed thatthe sample had been realized upconversion white luminescence output. According tothe power curve, it was speculated that the upconversion blue luminescence is threephoton process, the upconversion green luminescence is two photon process, theupconversion red luminescence is two photon process and three photon process. Theupconversion mechanism was analyzed on the basis.