Analysis of the Exciton Luminescence of Silicon for Characterization of the Content of Impurities

Abstract

The low-temperature exciton luminescence of silicon has been measured and analyzed on the basis of rate equations describing the formation and decay kinetics of free exciton, bound exciton and bound multiexciton complexes. In particular, the excitation-level and impurity-concentration dependences of the luminescence-intensity ratio of bound exciton to free exciton have been investigated in detail so as to characterize the content of dopant impurities in silicon. Analysis of experimental data for boron-doped silicon has shown that the dopant-impurity concentration and the compensation ratio by phosphorus donors can be quantitatively estimated from the exciton-luminescence data. These results suggest that analysis of exciton luminescence is a promising technique in silicon crystal characterization.