THERMOLUMINESCENCE, FLUORESCENCE, AND OPTICAL ABSORPTION STUDIES ON SINGLE CRYSTALS OF RUBIDIUM IODIDE DOPED WITH Eu**2** plus .

Abstract

Thermoluminescence, optical absorption, and fluorescence studies on the RbI:Eu**2** plus system indicate that the Eu**2** plus ions act as donors on irradiation and thereby convert to the Eu**3** plus ions. On thermal and (or) optical treatment the electrons released are captured back. The integrated light intensity of the system is an order of magnitude higher than that of the undoped samples. Fluorescence measurements show an emission around 2. 83 ev. Thermoluminescence emission spectra give two emission bands peaking around 2. 48 and 2. 83 ev. A tentative energy band diagram is suggested explaining these emissions. Excitation of irradiated samples with F light is used to support this model.