Molecular dynamics simulation of the effects of neutron irradiation on Caesium Lead Bromide

TL;DR

This paper uses molecular dynamics and Monte Carlo simulations to analyze how neutron irradiation affects Caesium Lead Bromide at the atomic level, informing its potential as a radiation-hardened neutron detector.

Contribution

It provides the first detailed molecular-level analysis of neutron irradiation effects on CsPbBr$_3$, including vacancy and interstitial atom distributions and displacement thresholds.

Findings

Displacement threshold energies for CsPbBr$_3$ atoms identified.

Distribution patterns of vacancies and interstitials mapped over time.

PKA and DPA data obtained for neutron-irradiated CsPbBr$_3$.

Abstract

With the development of fast neutron reactors and nuclear fusion reactors, it is necessary to find new radiation-hardened high-flux core neutron detectors. The use of perovskite Caesium Lead Bromide (CsPbBr$_3$) for neutron radiation detection is a new research direction. However, at high temperatures, the effects of neutron radiation, especially the Primary Knock-out Atom (PKA) and Displacement Per Atom (DPA), and the defect distribution at the molecular level have not been reported. This study investigated the effect on CsPbBr$_3$ produced by 14 MeV neutron irradiation under 100 K to 400 K. Molecular dynamics methods are used to model the distribution of vacancies and interstitial atoms at the molecular level of materials. This study obtained the displacement threshold energies of three atoms in CsPbBr$_3$ and obtained the distribution of vacancies and interstitial atoms within the material over time. Monte Carlo simulations were used to obtain PKA and DPA information in CsPbBr$_3$ under neutron irradiation. This research will help to further study the performance changes of halide perovskites under neutron irradiation to verify the possibility of using them as radiation-hardened neutron detectors.