2ND-ORDER RAMAN-SCATTERING OF SMALL GE PARTICLES IN RESONANCE WITH THE E(1) AND E(1)+DELTA-1 EDGES

Second-order Raman spectra of Ge particles with sizes of about 10 nm have been studied under resonance with the E1 and E1 + DELTA1 edges. The obtained spectra are analyzed in terms of discrete electronic and vibrational energy levels and in terms of the surface phonon mode. The discreteness of those eigenstates yields a decrease in the scattering rate of holes due to the k approximately 0 phonons in the small particles. A Raman band located just below the 2TO-phonon band is attributed to the scattering by two surface phonons.