How can I manage individual cell values of a mesh in a convergence process?

Using module Semiconductors for computing Electric Potential for a certain geometry, sometimes during convergence process one can observe how few cells close to both exterior limits of a domain and contacts (ohmic or Schottky), assume values clearly far from the expected. These sets of cells constitute a sort of splodges which prevent convergence uselessly. How to eliminate them? Can I manage the individual cell values in those cases when I am completely sure of a more appropriate ones?