Get access

Initial charge carrier dynamics in porous silicon revealed by time-resolved fluorescence and transient reflectivity



Nonequilibrium charge carrier relaxation dynamics in porous silicon was investigated by means of time-resolved photoluminescence and ultrafast transient reflectance. Fluorescence band shift to the low energy side and intensity decay were observed during several initial nanoseconds under porous silicon excitation at 3.3 eV, and attributed to the spectral diffusion and trapped carrier recombination. Ultrafast transient reflectance pump–probe technique reveals reflectance dynamics on a several ps time scale present with 3.1 eV excitation, but absent with excitation at 1.77 eV.