Microwave sol–gel (MSG) based yellow phosphors of LiNaCaLa(MoO4)3 quadruple molybdate with variations of LixNa1−x (x = 0.05, 0.1, 0.2, 0.3, 0.4) under the constant doping amount of Yb3+ = 0.45, Ho3+ = 0.05 were successfully fabricated, and the effect of Li+ of their spectroscopic characteristics were investigated. Under excitation derived from 980 nm, the final particles led to the formation of yellow emissions, which were resulted from the transitions of Ho3+ from the 5S2/5F4 → 5I8 in the green emission area, as well as from the 5F5 → 5I8 in the red emission area. The incorporation of Li+ ions led to the local symmetry distortion around the cations in the substituted crystal structure by the Yb3+ and Ho3+ ions, and further increased the UC transition probabilities in the quadruple molybdate of LixNa1−xCaLa0.5(MoO4)3: $$ {\text{Yb}}^{3 + }_{0.45} /{\text{Ho}}^{3 + }_{0.05} $$ Yb 0.45 3 + / Ho 0.05 3 + . The optimal condition was resulted from the composition of Li0.3Na0.7CaLa0.5(MoO4)3: $$ {\text{Yb}}^{3 + }_{0.45} /{\text{Ho}}^{3 + }_{0.05} $$ Yb 0.45 3 + / Ho 0.05 3 + for the yellow emitting diode based on the UC emissions and the chromaticity coordinates of CIE.