2, Baylor University, Waco, Texas, United States
Polymeric conductor poly(3,4-ethylenedioxythiophene)(PEDOT) has wide applications as transparent and flexible electrodes in electronic devices such as solar cells, organic light emitting diodes (OLEDs) and organic field effect transistors (OFETs). The electrical conductivity is the key property of PEDOT. Previously, the electrical conductivity of PEDOT has been reported to vary from 0.1 S/cm to 8797 S/cm (single crystal nanowires). Here, the electrical conductivity of PEDOT thin films as high as 6259 S/cm has been achieved using oxidative chemical vapor deposition(oCVD) with a growth temperature of 300. The influences of deposition temperature, post-growth acid treatment and film thickness are systematically studied. X-ray diffraction (XRD) reveals a crystallite configuration transition from edge-on to face-on with increasing growth temperature and decreasing film thickness. With the measured work function, Seebeck coefficient and temperature-dependent electrical conductivity, theoretical analysis reveals a metallic nature of the highly conductive polymer film, and suggested a theoretical mobility as high as 19.3 with Kang-Snyder model based on Boltzmann transport. In the end, a rectifier based on the PEDOT-Si diode working at 13.6 MHz is demonstrated utilizing the high mobility of the PEDOT material. Wafer scale fabrication of the radio frequency rectifier is demonstrated as a powerful feature of the oCVD process.