Fig. 2: Electrical contact properties of transferred-Pt, transferred-Au, and evaporated-Au monolayer C10-DNTT OTFTs.
From: Ultralow contact resistance in organic transistors via orbital hybridization
a Room temperature ID~VGS characteristics of a typical TLM structure of transferred-Pt OTFTs with a channel length of 0.9, 2.0, 3.6, 4.6, and 7.2 μm under VDS = −1.0 V. The TLM structure has the same channel width of 27 μm. Inset shows the scanning electron microscope (SEM) image of TLM structure. Scale bar, 30 μm. b Rc extraction using TLM method from the device in a. c Histogram of the contact resistance of transferred-Pt OTFTs. d The Rc as a function of temperature in three types of OFETs. The contact resistances in c, d were extracted at VDS = −1.0 V and n2D = 7.9 × 1012 cm−2. e Arrhenius plots of the Ohmic transferred-Pt (red open circle) and transferred-Au (green open circle) OTFTs at VGS = −3.0 V and VDS = −0.3 V, and Schottky evaporated OFETs (blue open circle) at VGS = −3.0 V and VDS = −1.0 V, respectively. The channel length and width see Supplementary Figs. 5 and 7. f Statistics of effective mobility (μ), subthreshold swing (SS), on/off ratio (Ion/Ioff), and threshold voltage (Vth) of 42 transferred-Pt, 16 transferred-Au, and 21 evaporated-Au contact C10-DNTT OFETs with channel length more than 10 μm at room temperature. The average values are 15.8 (13.0/2.9) cm2 V−1 s−1, 61.6 (63.6/96.6) mV/decade, 2.24 × 108 (3.6 × 107/1.8 × 106), −0.18 (−0.26/−0.75) V, respectively, for transferred-Pt (transferred-Au/evaporated-Au) contact. The corresponding best values see Supplementary Table 2. g Rc distribution of several kinds of ultrathin organic crystalline films with three contact types of OTFTs with channel lengths ranging from 0.9 to 45 μm, respectively. f, g The black lines represent the average of statistical data. h State-of-the-art contact technology for OFETs plotted as a function of carrier concentration, showing the optimal Rc of various organic semiconductors. The solid black line represents the quantum limit for contact resistance. For references, see Supplementary Table 1. The symbols in h represent C10-DNTT (open circle), C8-BTBT (open square), Ph-BTBT-C10 (open star), C8-DNBDT-NW (open up triangle), C9-DNBDT-NW (open down triangle), Dph-DNTT (open diamond), IDTBT (open pentagon), Pentacene (open triangle), P3HT (solid diamond) and PDPP (solid left triangle), respectively.
