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A (C 6 H 5 C 2 H 4 NH 3 ) 2 PbI 4 crystal was prepared to investigate its photoluminescence (PL) and scintillation properties. Two PL emission peaks at 525 and 560 nm derived from the recombination of excitons were observed. The obtained PL decay curve was approximated from the sum of three exponential decay functions related to the excitonic luminescence. Under X-ray irradiation, the excitonic emission at 560 nm from shallow trap centers was observed, and the X-ray induced scintillation decay times were 0.8, 6.0, and 37 ns. The full energy peak was observed under 241 Am α-ray (5.5 MeV) irradiation, and the light yield was estimated to be ~2900 ph/5.5 MeV-α.

Undoped, 0.5, 1.0, and 2.0% Nd-doped Bi4Si3O12 (BSO) crystals were synthesized by the floating zone method. Regarding photoluminescence (PL) properties, all samples had emission peaks due to the 6p–6s transitions of Bi3+ ions. In addition, the Nd-doped samples had emission peaks due to the 4f–4f transitions of Nd3+ ions as well. The PL quantum yield of the 0.5, 1.0, and 2.0% Nd-doped samples in the near-infrared range were 67.9, 73.0, and 56.6%, respectively. Regarding X-ray-induced scintillation properties, all samples showed emission properties similar to PL. Afterglow levels at 20 ms after X-ray irradiation of the undoped, 0.5, 1.0, and 2.0% Nd-doped samples were 192.3, 205.9, 228.2, and 315.4 ppm, respectively. Dose rate response functions had good linearity from 0.006 to 60 Gy/h for the 1.0% Nd-doped BSO sample and from 0.03 to 60 Gy/h for the other samples.

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