Thermoluminescence Spectra of Lithium Tetraborate Single Crystal

Lithium tetraborate (LBO or LTO) single crystal seems to be a promising new material for thermoluminescent dosimeter (TLD) and SAW resonators. In the present work, thermoluminescence (TL) characteristic and TL spectra of LTO single crystal grown by Bridgman method were measured, the kinetic parameters of TL traps were calculated, and TL spectra were analyzed. The result shows: The primary glow peaks are at about 186oC and 313oC. The activation energies of the traps corresponding to the two TL peaks are 0.96eV and 1.56eV, and the frequency factors are about 7.94×109s-1 and 6.31×1012s-1. The TL spectra of LTO crystal extends from 350nm to 460nm, and has its maximum at about 381nm. The intrinsic luminescent centers can send the energy from crystal lattice to Cu+ ions, because the activation energies of two are quite similar, and the Cu+ ions become new luminescent centers to increase TL sensitivity when Cu ions are doped into LTO crystals.