Multi-particle effects in far-IR optical transmission spectra of Ge/Si quantum dots

Abstract

Photoinduced and equilibrium optical transmission was studied in undoped and δ-doped Ge/Si quantum dot structures in the far-infrared spectral range. Multi-particle excitations were observed in the absorption spectra of the structures with different doping levels. Photoinduced absorption spectra demonstrate the thermal distribution of the photoexcited holes over the single-particle states of the quantum dot ensemble in contrast with the equilibrium absorption spectra.