LUX-ZEPLIN

Abstract:

Gallium oxide has recently been identified as a promising scintillator. To assess its potential as a detector material for ionizing radiation at low temperatures, we measured the luminescence and scintillation properties of an undoped Ga2O3 crystal over the 7–295 K temperature range. The emission of the crystal is due to the radiative decay of self-trapped excitons and donor-acceptor pairs and peaks at a wavelength of 380 nm. The scintillation light output of the undoped Ga2O3 increases with a decrease in temperature, reaching a maximum value of 19 300 ± 2200 ph/MeV at 50 K. The measured luminescence kinetics has a recombination character with specific decay time (τ0.1) increasing from 1 to 1.8 μs at cooling. Since radiative decay in the crystal competes with nonradiative processes, material optimization could lead to the scintillator achieving a yield of 40800 ph/MeV, a figure considered to be an upper limit.

Abstract:

We report the excellent scintillation properties of MAPbBr3, an organic–inorganic trihalide perovskite (OTP). The characteristic scintillation time constants were determined using pulsed monochromatic 14 keV X-rays from a synchrotron. We find that between 50 and 130 K the MAPbBr3 crystal exhibits a very fast and intense scintillation response, with the fast (τf) and slow (τs) decay components reaching 0.1 and 1 ns, respectively. The light yield of MAPbBr3 is estimated to be 90 000 ± 18 000 ph MeV−1 at 77 K and 116 000 ± 23 000 ph MeV−1 at 8 K.