RAMAN VERSUS INTERBAND ABSORPTION IN GE QUANTUM DOTS

In this work, we pres ent evidence of quantum confinement effects on G e nanocrystals, grown by an evaporation-condensation technique, throug h the inspection of the above the gap spectral structures and the Rama n peak. In particular, when the nanoparticles size is reduced, the E-2 absorption peak shows a relevant blueshift, whereas the Gamma(5)(+): phonon peak has a contemporary broadening and redshift. This different behavior is related to the different curvature of the electronic and phononic bands which originate the structures. (C) 1998 Elsevier Scien ce S.A.