Optically Detected Magnetic Resonance in Amorphous Semiconducting Glasses

Abstract

Although it has been assumed for many years that photoluminescence in materials such as the chalcogenide glasses is due to a single recombination process, recent optically detected magnetic resonance (ODMR) studies have shown that both exciton and pair processes are involved. This paper will briefly outline the techniques and principles of ODMR as applied to both crystalline and amorphous materials, and illustrate the importance of the method by a consideration of recombination at triplet exciton states in glasses. Amorphous phosphorus has become the model material for these investigations, and the relationship between the ODMR, luminescence lifetime and time resolved results will be used as a basis for discussing parallel results in the chalcogenide glasses, where, in particular, new luminescence measurements of both the crystals and the related glasses can be compared with the ODMR results. The investigations establish the ODMR technique as an important method for analyzing the recombination processes in these and other amorphous semiconductors.