Concentration Dependence of Quantum Efficiency of Luminescence in KCl: Tl

Quantum efficiency measurements for the 3050 A emission band of KCl: Tl under 2470 A excitation are reported and compared with earlier data. In the present work, the average quantum efficiency is found to be 80±5% over a concentration range of 4×${10}^{-3\mathrm{}}$ to 8×${10}^{-1\mathrm{}}$ mole percent Tl. Concentration quenching, if it exists in this range, is only slightly greater than the experimental error. This result is consistent with the Dexter-Schulman proposal of the importance of transfer processes in concentration quenching.