LiInSe2 for Semiconductor Neutron Detectors

Abstract

Lithium indium selenide (LiInSe 2) is being developed for use as a room temperature semiconductor detector for thermal neutrons. The material has been studied for a number of applications including non-linear optics such as parametric oscillators, as anode material for lithium ion batteries, piezoelectrics, as a scintillation detector material, and as a semiconductor detector material. The recent advances of the crystal growth, material processing, and detector fabrication have led to semiconductor neutron detectors with up to 100 mm 2 active area. The theoretical thermal neutron detection sensitivity and gamma rejection ratio (GRR) are comparable to 10 atm, 3 He tubes of similar size. Detector fabrication and characterization are described and the results are discussed.

Thermal neutron detection with lithium-based semiconductors

“…For a neutron detector with a Li-based compound semiconductor in Figure 1, while the neutron absorption efficiency can theoretically approach 100% as the detector thickness increases; the neutron detection efficiency due to the 6 Li(n,α) 3 H reaction saturates below 100%, due to competing reaction of the thermal neutrons with other isotopes than 6 Li, which generate a negligibly small signal charge. The neutron detection efficiency due to the 6 Li(n,α) 3 H reaction is plotted in Figure 2 based on the fundamental relationship between the macroscopic thermal neutron absorption cross-section of the composition, microscopic thermal neutron absorption cross-sections of all elements, the density of the compound, and the thickness of the detector as previously outlined [1].…”

Review of direct neutron conversion and detection processes

“…Below in Figure 2 is shown an image of an ingot taken from the Reference -6 LiInSe2 ingot [9] https://www.frontiersin.org/articles/10.3389/fphy.2020.00078/full…”

Robust Thermal Neutron Detection by LiInP2Se6 Bulk Single Crystals

“…Nevertheless, it is challenging to design materials with a set of structure and property features suitable for direct neutron detection. During the past decade, two candidate material systems, BN and LiInSe 2 , [16][17][18][19][20][21][22][23][24] have been extensively studied from aspects of crystal growth, defect analysis, characterization of carrier properties, testing of prototype detectors, etc. Albeit with verified neutron detectability, the overall performance of both systems has yet to reach a level that encourages commercial applications (also note that BN requires a costly thickepilayer fabrication route using metal-organic chemical vapor deposition).…”