Accurately predicting optical properties of rare-earth, aluminate scintillators: influence of electron–hole correlation

Abstract

A theoretical and computational analysis of two approaches to simulate luminescent profiles of rare-earth perovskite scintillators is given. This work establishes the importance of many-particle corrections in the prediction of the principal excitation wavelength, revealing that they lead to differences of nearly one hundred nanometers from the standard Δ-SCF approach. We show the electronic structure of this class of materials uniquely necessitates a many-particle treatment because, in contrast to traditional semiconductors, rare-earth scintillator materials are weakly screened and relatively few bands dominate the radiative decay channels. This makes accounting for long-range electron–hole correlations a central issue in accurate predictions, and we discuss the trade-off between accuracy and performance of various popular approaches. Understanding the strengths and weaknesses of available theoretical tools will help define search parameters for new scintillator development.