The effect of the PEDOT:PSS surface energy on the interface potential barrier

Commercial PEDOT:PSS dispersions have been used to study the PEDOT:PSS interface properties; ITO/PEDOT:PSS/Al devices have been analyzed by the means of current-voltage and capacitance-voltage measurements where the effect of a barrier has been observed. Then by contact angle measurements employed on the PEDOT:PSS layer, the surface energy has been compared to the built-in potential obtaining an empirical law relating the polar component of the energy with the internal potential. The results have been interpreted in terms of interaction between the organic permanent dipoles and the metal that favours the tuning of the built-in potential. (C) 2011 Elsevier B.V. All rights reserved.