Intrinsic lithium indium diselenide: Scintillation properties and defect states

Evaluation of Neutron‐Radiation Tolerance of Lithium Indium Diselenide Semiconductors

“…Also, the intensity ratio of the Li-Se peaks to the A 1 symmetry peak (161 cm À1 ) in the previous literature was much smaller for the irradiated and red samples compared to as-grown yellow samples. [18] This relationship was also observed for the RMD-grown samples irradiated in this study. It should also be noted that the LISe sample irradiated in prior work had a Raman spectrum where one of the Li-Se peaks grew larger than the symmetry peak, while the opposite occurred for all samples irradiated in this study.…”

“…Due to LISe having an orthorhombic structure with point symmetry group C 2v (mm2) chemical structure, it should have 11 vibrational modes below 100 cm −1 and 8 modes above. [ 18,25–27 ] Previous literature has assigned the three largest peaks below 161 cm −1 to the Li—Se bonds and the three largest peaks above 161 cm −1 to the In—Se bonds. [ 28 ] The large peak at 161 cm −1 is the A 1 symmetry peak.…”

“…Similar peaks have been detected in previous work, where the higher intensity green peak results from the transition between the In Li 0/− → Li In 0/+ antisites and the lower intensity red emission results from the transition between the In Li +/2+ → Li In −/2− antisites. [ 18,23 ] Stereotypically, green emission is observed in yellow LISe samples and red emission in red LISe samples, but this correlation requires further study. [ 18,23 ] A smaller 410 nm peak was also observed in preirradiated samples 2 and 4 that were not reported in past literature.…”

“…The LISe crystals were prepared using a two-step synthesisgrowth procedure by Radiation Monitoring Devices, Inc. (RMD). [18] In and Se were purchased from Alfa Aesar and 95% enriched 6 Li was obtained from the ONRL Isotope office. The first step was synthesized by the mixing of Li metal with In metal, followed by the reaction of Se vapor with the Li-In molten alloy.…”

“…Since LISe has exhibited both effective semiconducting and scintillating properties, its luminescence mechanisms provide insight into its electronic properties. [14,16,18] The luminescent emissions have only tentatively been assigned to certain donor-acceptor pairs (DAPs) in the literature, where the DAP density is correlated to the luminescent intensity. [14,22,23] All LISe sets were exposed to a 35 keV CMX003 Bremsstrahlung X-ray source at 0.1 mA.…”