A description of Schottky barrier for n-type semiconductors will be given here and particular attention will be devoted to the thermodynamics of Gibbs free energy. Thereby, a description of the Fermi level in terms of electrochemical potential of the electrons will be provided. To this purpose we determined the density of surface states as a function of the mean grain radius, which establishes the Schottky barrier height. The inter-granular potential shape was investigated in depletion approximation under spherical geometry and a revision of this method was proposed when the grain is smaller than a critical dimension. The model was then extended to include oxygen in and out diffusion, with the mass action law made independent of Fermi level position. Thus we were able to explain the pinning of Fermi level in SnO2 and tunnelling through the barrier to model the experimental conductance variation.
Surface states and oxygen in-diffusion in nanostructured SnO2
MALAGU', Cesare
2010
Abstract
A description of Schottky barrier for n-type semiconductors will be given here and particular attention will be devoted to the thermodynamics of Gibbs free energy. Thereby, a description of the Fermi level in terms of electrochemical potential of the electrons will be provided. To this purpose we determined the density of surface states as a function of the mean grain radius, which establishes the Schottky barrier height. The inter-granular potential shape was investigated in depletion approximation under spherical geometry and a revision of this method was proposed when the grain is smaller than a critical dimension. The model was then extended to include oxygen in and out diffusion, with the mass action law made independent of Fermi level position. Thus we were able to explain the pinning of Fermi level in SnO2 and tunnelling through the barrier to model the experimental conductance variation.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
