In-Situ Measurements of Organic Electronic Devices Fabricated via Transfer Printing on Flexible Substrates

Transfer printing was used to fabricate high quality organic thin-film transistors (TFT) on flexible substrates.~ The model system of a pentacene (Pn) TFT with 600 nm thick poly(methyl methacrylate) dielectric layer and gold electrodes on a polyethylene terephthalate substrate has shown a mobility (adjusted for contact resistance) of 0.237 cm$^{2}$/Vs, on/off ratio of 10$^{5}$ and threshold voltage of -7 V.~ To optimize the transfer printing parameters of the Pn semiconductor layer, mobility and contact resistance were studied as a function of printing temperature and pressure.~ The best TFT devices resulted from printing at 120 $^{o}$C and 600 psi.~ A detailed study of the effect of transfer printing on the device properties was performed via in-situ measurements of drain current (ID) as a function of both drain (VD) and gate (VG) voltages.~ Details of the in-situ measurements while transfer printing the Pn layer will be presented and discussed. *Work supported by the Laboratory for Physical Sciences, College Park, MD and ARDA.