Improved growth technique for high-quality trans-stilbene single crystals achieving a record PSD performance.

Trans -stilbene single crystal possesses the advantages of high luminescence efficiency, short response time, stable radiation/strong light resistance and remarkable neutron/gamma pulse shape discrimination (PSD) properties, rendering it arguably the leading candidate for organic scintillators. Here, by the improvement of the thermal field, solvent and sealing on our self-designed equipment, precise growth control resulted trans -stilbene single crystal with high crystalline quality (half peak width of rocking curve of 46.58 arcsec) and size of more than 60 mm. Then we fabricated crystal wafers for the first time to conduct systematic physicochemical measurements to reveal the intrinsic properties of the material. The high-quality single crystals were found to possess high optical transmittance (80%), fast decay time of 2.85 ns (68.49%) and high photoluminescence quantum yield (90.5%), which are more suitable for fast neutrons detection requirements. Thirdly, we conducted a comprehensive exploration of the radiation response of high-quality trans -stilbene single crystals to alpha particles and gamma rays. The results showed a record neutron/gamma discrimination performance with a FOM value of 4.33, which is the highest reported value so far. This work paves the way for practical applications of trans -stilbene and may provide guidance for the selection of detectors for monitoring ionizing radiations under multiple irradiations background. • Large-sized and high-quality trans -stilbene single crystals were grown by our independently designed growth equipment. • The fabrication of wafers from the as-grown single crystals were firstly realized to measure the physical/chemical properties. • The n/γ discrimination of trans -stilbene single crystals showed a FOM value of 4.33, which is the highest value so far. [ABSTRACT FROM AUTHOR]