Optical and scintillation properties of modified LSO crystals with different ions doping grown by a rapid CZ system

Abstract

LSO:Ce is a well-known scintillation crystal that is widely used in nuclear medicine, security checks, and high-energy physics. The scintillation properties of LSO can be modified by doping to meet the ever-growing requirements of radiation detection. However, exploring new doping techniques for LSO crystals with self-designed scintillation features remains time-consuming, especially by the Czochralski (CZ) method. In this paper, we established a high-efficiency crystal growth system based on the CZ method for the rapid growth of LSO crystals. The system is regulated by a high-accuracy auto-diameter controller to grow small boules of ϕ 20 mm × 100 mm. By incorporating an arc bottom crucible and optimizing the temperature field, the crystallization fraction of the as-grown crystal can be increased to 95% with the growth period compressed to 48 h. With the aid of the growth system, LSO crystals with Lu3+ partially substituted by optical inertia RE ions (Sc3+, Y3+, La3+, Gd3+), metal cations co-doping (Ca2＋, Li1+, Yb3+), and different luminescent ions doping (Pr3+, Nd3+, Eu3+, Tb3+, Dy3+, Yb3+) are grown. Comparative analysis shows that the Ca co-doped LSO:Ce exhibits the best scintillation performance, taking into account both light output and decay time, among our samples. Moreover, Tb-doped LSO features relatively good scintillation efficiency with various wavelengths of visible light emission.