Investigation of fatigue relaxation of luminescence in porous silicon by time-resolved spectroscopy

Abstract

This paper describes the first investigations of how the intensities of various time-resolved components of the luminescence from porous silicon relax with time. A paradoxical correlation is observed between the macro-and microtemporal relaxation of luminescence from porous silicon under pulsed photoexcitation: namely, a relative increase in the rate of macrorelaxation for the slower components of the luminescence. Spectral investigations show that the difference in the rates of fatigue relaxation “tiredness” is maximum at the long-wavelength edge of the luminescence band. We propose a model that allows us to explain the observed effects starting from the assumption that photoexcitations drift toward radiative recombination centers.