Highly enhanced photoluminescence of YBO3:Eu3+ micro-spheres by co-adding Li ion and alkaline-earth metal ions

► Well dispersed YBO3:Eu3+ micro-spheres are synthesized by a hydrothermal route. ► Perfect surface and enlarged size is achieved by adding ions. ► PL emission doubles when co-adding Li+ and alkaline-earth metal ion at 220°C.