中文摘要：

焦硅酸镥掺铈（LPS：Ce）具有突出的闪烁性能,比如高光产额和快衰减,但晶格中的氧空位会影响其闪烁性能.本文通过第一性原理方法研究了Li,Na,Mg和Ca在LPS中的稳定性和对氧空位的影响.结果表明：在缺氧环境下,这些离子倾向于占据间隙位,从而可能抑制氧空位.分析了杂质离子对LPS电子结构的影响.

英文摘要：

Lu2Si2O7 ： Ce （LPS： Ce） is a well-known scintillator due to its excellent scintillation properties such as high light yield and fast decay time. However, the oxygen vacancies would degrade its scintillation properties. In this paper, we perform first-principles investigation on the stabilities of Li, Na, Mg and Ca in LPS and their influences on the oxygen vacancy. We focus on the defect formation energies and densities of states. It is found that the dopants occupy interstitial sites under oxygen-poor limit. They can suppress oxygen vacancies due to the requirement of charge balance. We discuss the influence of dopants on the density of states of perfect LPS.