Temperature dependence of the current-voltage characteristics of Sn/PANI/p-Si/Al heterojunctions

Kaya M., Cetin H. , Boyarbay B., Gok A., Ayyildiz E.

JOURNAL OF PHYSICS-CONDENSED MATTER, vol.19, no.40, 2007 (Journal Indexed in SCI) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 19 Issue: 40
  • Publication Date: 2007
  • Doi Number: 10.1088/0953-8984/19/40/406205


Sn/ PANI/ p- Si/ Al heterojunctions were fabricated by electropolymerization of aniline on chemically cleaned p- Si substrates. Current - voltage characteristics of Sn/ PANI/ p- Si/ Al heterojunctions measured in the temperature range 140 280 K are presented and analyzed. Although these devices were clearly rectifying, their I - V characteristics were non- ideal, which can be judged from the nonlinearity in the semi- logarithmic plots. The high values of the ideality factor n depending on the sample temperature may be ascribed to a decrease of the exponentially increasing rate in current due to space- charge injection into the PANI thin film at higher forward bias voltages. Careful analysis of the forward bias I - V characteristics on a log - log scale indicates that the space-charge-limited current ( SCLC) conduction controlled by an exponential trap distribution above the valence band edge dominates the current transport in the PANI/ p- Si diodes at high voltages. Furthermore, the PANI was characterized by using Fourier transform infrared ( FTIR) and ultraviolet - visible ( UV - vis) spectra.