Microscopic Mechanism of the Heat‐Induced Blueshift in Phosphors and a Logarithmic Energy Dependence on the Nearest Dopant–Vacancy Distance

Heat‐induced blueshift (HIB) observed in many luminescent materials is a puzzling phenomenon that has remained unexplained for decades. By using the high‐throughput first‐principles calculations and energy‐screening techniques, we generated a number of model structures for five phosphors, RbLi[Li3SiO4]2:Eu2+, Na[Li3SiO4]:Eu2+, K[Li3SiO4]:Eu2+, Sr[LiAl3N4]:Eu2+, and Ca[LiAl3N4]:Eu2+. Our analyses suggest, to a first approximation, a logarithmic energy dependence on the nearest distance between the dopant and the metal‐cation vacancy. By identifying the 5d→4f transition energies from the electronic structures calculated for the screened model structures, we show that the vibration of the Eu2+ ion lying in an asymmetric and anharmonic potential well couples with the electronic states, leading to their HIB phenomena. A logarithmic relation governing the structures of phosphors was revealed together with an electron–phonon coupling mechanism explaining the heat‐induced blueshift (HIB) phenomenon by using a high‐throughput first‐principles approach. The results shed new light on understanding the general structure problems of defect‐containing systems, and the heat‐induced phenomena of phosphors.