Crystal growth and scintillation properties of Tm³⁺ doped LaCl₃ single crystal for radiation detection

Single crystal of Tm-doped LaCl₃ (LaCl₃:Tm³⁺) with the dimension of diameter 7 mm and length 55 mm was successfully grown using an in-house-developed Bridgman furnace. The grown crystal has the self-trapped exciton (STE) emission in the range of 300–500 nm along with the characteristic emissions corresponding to the 4f-4f transition of Tm³⁺ ions under X-ray excitation. The scintillation characterizations of the grown crystal were performed by pulse height spectra, scintillation decay time, as well as pulse shape discrimination studies under γ-ray and α-particle excitation sources. The LaCl₃:Tm³⁺ crystal was found to have a high light yield (42,000 ± 4,200 ph/MeV) with 4.2% energy resolution under γ-rays excitation. Moreover, the pulse shape discrimination was studied using ¹³⁷Cs and ²⁴¹Am as the radiation sources with a good FOM value. The results conclude the LaCl₃:Tm³⁺ single crystal to be a promising candidate for X-ray and γ-ray detection purposes.