Characterization and improvement of the contact between indium tin oxide and triphenyl diamine-doped polycarbonate

We have measured the electrical characteristics at the contact between indi um tin oxide (ITO) and the molecularly doped polymer N-N'-diphenyl-N-N'-bis (3-methylphenyl)-1-1-biphenyl-4,4'-diamine-doped polycarbonate (PC:TPD). We find that the contact is current-limiting, supplying the sample with a cur rent that is considerably smaller than the space charge limited Current. Wh en an ultra-thin layer of Pt or Pd is introduced between ITO and PC:TPD an increase in the injected current is observed as the contact becomes ohmic. (C) 2001 Elsevier Science B.V. All rights reserved.