Crystal growth, scintillation properties and silicon-germanium ratio concentration optimization of BGSO: An excellent scintillator for dual-readout calorimeter.

• BGSOs with different Si/Ge ratio are successfully grown by Bridgman technique. • The scintillation properties of BGSOs with different Si/Ge ratio are investigated. • Si/Ge–O and Bi–O interactions play a critical role in the band gap of BGSO. • BGSO shows great potential for application in dual readout calorimeters. Bismuth silicate-germanate (Bi 4 Ge 3x Si 3(1-x) O 12) crystals are successfully grown with the modified Bridgman technique. The X-ray diffraction, transmittance spectra, radioluminescence spectra and scintillation properties of these crystals are investigated at different ratios of Ge and Si. Furthermore, the XEL peaks of BGSO crystals exhibit a red-shift with the increase of Ge content. Meanwhile, the light yield and energy resolution of crystals represent obviously variation with changing of Ge and Si contents in the crystal. Density-functional theory (DFT) calculations were performed for energy band structure and geometry optimizations of Bi 4 Ge 2.4 Si 0.6 O 12 crystal. The calculated energy band of BGSO crystal is 3.957 eV, which is different from that of BSO and BGO crystals. The results of DOS and PDOS calculated by CASTEP package reveal that Si/Ge–O and Bi–O interactions play a critical role in the band gap of BGSO crystal. [ABSTRACT FROM AUTHOR]