Chapter 4 Photoluminescence I: Theory

This chapter discusses the theory of photoluminescence. The semiclassical formalism is retained but modified to include spontaneous emission in a natural if nonrigorous manner. An effort is made to write the results in a form that can be transcribed by inspection to a full quantum electrodynamical formalism. Within this conglomerate formalism, formulas to describe recombination processes are developed on equal footing with absorption processes without recourse to detailed balance. Detailed balance is also recognized as a powerful tool in its own right and is accorded “equal time.” In addition, an expanded discussion of optical transitions involving “effective mass” impurities with degenerate states is presented, and the “quantum defect” technique is applied to determine good approximate wave functions for deep impurity levels which, in turn, are used to calculate the dependence of band impurity transition rates on binding energy.