Radioluminescent mechanism of Li2B4O7:Cu crystal

Abstract The structure of the radioluminescent (RL) spectrum of Li 2 B 4 O 7 :Cu crystal is complex, having no normal Gauss peaks. The RL spectrum recorded showed one sharp and strong peak near 365 nm. For the purpose of explaining this phenomenon, we used the self-trapped exciton (STE) model to analyze experimental data of absorption spectrum, emission spectrum, radioluminescence spectrum and decay-time curves. We found a short lifetime component (of the order of ns) from phosphorous signals of Li 2 B 4 O 7 :Cu. We realized that the short lifetime component related to inherent signal of host lattice and the d–p transitions of Cu + . This result is applicable in the detector system with high time resolution.

[1]  J. Aarik,et al.  Spectral narrowing of self-trapped exciton emission in anatase thin films , 2001 .

[2]  J. G. Solé,et al.  An Introduction to the Optical Spectroscopy of Inorganic Solids , 2005 .

[3]  A. Watterich,et al.  Luminescence characteristics of Cu- and Eu-doped Li2B4O7 , 2004 .

[4]  B. Moine,et al.  Optical spectroscopy of monovalent copper-doped borate glasses , 1990 .

[5]  M. Proki.  Dosimetric Characteristics of Li2B4O7:Cu,Ag,P Solid TL Detectors , 2002 .

[6]  H. Chau,et al.  Effect of doping on the luminescence properties of Li2B4O7 , 2008 .

[7]  C. Eijk.  Development of inorganic scintillators , 1997 .

[8]  I. N. Ogorodnikov,et al.  Self-trapped excitons in LiB3O5 and Li2B4O7 lithium borates: Time-resolved low-temperature luminescence VUV spectroscopy , 2000 .

[9]  D. McClure,et al.  The3d→4ptransitions ofCu+in LiCl and of transition-metal ions in crystals , 1977 .

[10]  M. P. Dergachev,et al.  Raman scattering in Li2B4O7 crystals with impurities , 2001 .

[11]  K. Ucer,et al.  Picosecond excitonic luminescence in ZnO and other wide-gap semiconductors , 2004 .

[12]  B. Moine,et al.  Kinetic investigations of NaF: Cu luminescence , 1984 .

[13]  Tomohiro Adachi,et al.  Crystal growth and luminescence properties of Li2B4O7 single crystals doped with Ce, In, Ni, Cu and Ti ions , 2002 .

[14]  T. Oku,et al.  Boron based oxide scintillation glass for neutron detection , 2005 .

[15]  M. Matsuoka,et al.  Thermoluminescence Mechanism In Li2B407:Cu , 1996 .