X-ray photoemission spectroscopy and optical absorption studies have been carried out on nanoparticles prepared using the activated reactive evaporation technique. A strong shift of the valence band edge (from 0.7 to 1.8 eV) has been observed on reduction of the nanoparticle size from 20 nm to 4 nm. The size-dependent modifications in the energy level diagram and nanoparticle Schottky junction characteristics confirm the observation of the inversion of conductivity type from -type bulk conductivity to -type conductivity in nanoparticles at lower dimensions. This study can initiate a further methodology for tailoring the semiconductor properties of a material by controlling the nanoparticle size.
- Received 3 July 2003
- Revised 20 January 2004
- Published 29 April 2004
© 2004 The American Physical Society