Hybrid halide perovskite neutron detectors

Abstract

Interest in fast and easy detection of high-energy radiation (x-, γ-rays and neutrons) is closely related to numerous practical applications ranging from biomedicine and industry to homeland security issues. In this regard, crystals of hybrid halide perovskite have proven to be excellent detectors of x- and γ-rays, offering exceptionally high sensitivities in parallel to the ease of design and handling. Here, we demonstrate that by assembling a methylammonium lead tri-bromide perovskite single crystal (CH3NH3PbBr3 SC) with a Gadolinium (Gd) foil, one can very efficiently detect a flux of thermal neutrons. The neutrons absorbed by the Gd foil turn into γ-rays, which photo-generate charge carriers in the CH3NH3PbBr3 SC. The induced photo-carriers contribute to the electric current, which can easily be measured, providing information on the radiation intensity of thermal neutrons. The dependence on the beam size, bias voltage and the converting distance is investigated. To ensure stable and efficient charge extraction, the perovskite SCs were equipped with carbon electrodes. Furthermore, other types of conversion layers were also tested, including borated polyethylene sheets as well as Gd grains and Gd2O3 pellets directly engulfed into the SCs. Monte Carlo N-Particle (MCNP) radiation transport code calculations quantitatively confirmed the detection mechanism herein proposed.

Halide perovskites and perovskite related materials for particle radiation detection

“…Therefore, it is important to find the optimized device thickness for balanced neutron detection efficiency and γ-ray sensitivity. Indirect-conversion detectors based on MAPbBr 3 were also reported by Andričević et al 115 The detectors employed a simple device structure of MAPbBr 3 single crystals with graphite spray electrodes. A Gd foil or a Gd 2 O 3 pellet was used for neutron conversion.…”

“…Several reports have demonstrated neutron detectors based on halide perovskites, including both scintillators and indirect-conversion solid-state detectors. [67][68][69][70]106,115,116 Since the detectors for thermal and fast neutrons require different absorbing materials, they will be discussed separately below.…”

Lithium Chloride-Substituted Methylammonium Lead Tribromide Perovskites for Dual γ/Neutron Sensing

“…Several methylammonium (MA)-based MHP variants have already shown spectroscopic capabilities, such as MAPbI 3 and Cl compensated MAPbBr 3 , which demonstrated resolutions of 6.8% at 122 keV and 6.5% at 662 keV, respectively. ,, Single-crystal (SC) methylammonium lead tribromide (CH 3 NH 3 PbBr 3 , MAPbBr 3 , or MAPB) has also demonstrated fast neutron sensing capability via elastic scattering from the 50% atomic fraction of hydrogen . Neutron sensing was also achieved to some degree through the incorporation of gadolinium oxide pellets into the MAPB as well as the use of boron conversion layers and gadolinium oxide heterojunctions. , Furthermore, studies in recent years already show that stoichiometric substitutions in the MAPB SC growths are achievable to produce functional devices for radiation sensing. ,,, While previous anion and cation substitutions were intended to increase device stability and improve electronic properties, no publications have yet reported on incorporating thermal neutron-sensitive elements into the MHP structure for dual γ/thermal neutron sensing.…”

“…12 Neutron sensing was also achieved to some degree through the incorporation of gadolinium oxide pellets into the MAPB as well as the use of boron conversion layers and gadolinium oxide heterojunctions. 8,18 Furthermore, studies in recent years already show that stoichiometric substitutions in the MAPB SC growths are achievable to produce functional devices for radiation sensing. 14,16,19,20 While previous anion and cation substitutions were intended to increase device stability and improve electronic properties, no publications have yet reported on incorporating thermal neutron-sensitive elements into the MHP structure for dual γ/thermal neutron sensing.…”

Comment on “Solid-State Neutron Detection Based on Methylammonium Lead Bromide Perovskite Single Crystals”

“…Hybrid halide perovskite-based radiation detectors have shown great improvement in recent years and their field of application has quickly widened from X-ray and gamma detection to α particle detection and recently to neutron detection . In the case of neutrons, there is a particular interest in the detection of thermal neutrons, as those are broadly used in neutron scattering applications, nuclear reactors, medical practice, etc.…”