Decoding the Vertical Phase Separation and Its Impact on C8-BTBT/PS Transistor Properties
20 March 2018

Ana Pérez-RodríguezInés TemiñoCarmen OcalMarta Mas-Torrent*, and Esther Barrena*ACS Appl. Mater. Interfaces201810 (8), pp 7296–7303. DOI: 10.1021/acsami.7b19279

Disentangling the details of the vertical distribution of small semiconductor molecules blended with polystyrene (PS) and the contact properties are issues of fundamental value for designing strategies to optimize small-molecule:polymer blend organic transistors. These questions are addressed here for ultrathin blends of 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) and PS processed by a solution-shearing technique using three different blend composition ratios. We show that friction force microscopy (FFM) allows the determination of the lateral and vertical distribution of the two materials at the nanoscale. Our results demonstrate a three-layer stratification of the blend: a film of C8-BTBT of few molecular layers with crystalline order sandwiched between a PS-rich layer at the bottom (a few nm thick) acting as a passivating dielectric layer and a PS-rich skin layer on the top (∼1 nm) conferring stability to the devices. Kelvin probe force microscopy (KPFM) measurements performed in operating organic field-effect transistors (OFETs) reveal that the devices are strongly contact-limited and suggest contact doping as a route for device optimization. By excluding the effect of the contacts, field-effect mobility values in the channel as high as 10 cm2 V–1 s–1 are obtained. Our findings, obtained via a combination of FFM and KPFM, provide a satisfactory explanation of the different electrical performances of the OFETs as a function of the blend composition ratio and by doping the contacts.


Hits: 2614
Oxides for new-generation electronics

Decoding the Vertical Phase Separation and Its Impact on C8-BTBT/PS Transistor Properties

Also at ICMAB

  • New Sensitive and Selective Chemical Sensors for Ni2+ and Cu2+ Ions: Insights into the Sensing Mechanism through DFT Methods

    09 April 2021 100 hit(s) Oxides
    We report the synthesis and theoretical study of two new colorimetric chemosensors with special selectivity and sensitivity to Ni2+ and Cu2+ ions over other metal cations in the CH3CN/H2O solution. Compounds (E)-4-((2-nitrophenyl)diazenyl)-N,N-bis(pyridin-2-ylmethyl)aniline (A) and (E)-4-((3-nitrophenyl)diazenyl)-N,N-bis(pyridin-2-ylmethyl)aniline (B) exhibited a drastic color change from yellow to colorless, which allows the detection of the mentioned metal cations through different techniques.
  • Silicon nanowires as acetone-adsorptive media for diabetes diagnosis

    06 April 2021 200 hit(s) Oxides
    Early detection of diabetes, a worldwide health issue, is key for its successful treatment. Acetone is a marker of diabetes, and efficient, non-invasive detection can be achieved with the use of nanotechnology. In this paper we investigate the effect of acetone adsorption on the electronic properties of silicon nanowires (SiNWs) by means of density functional theory.
  • Soft‐Chemistry‐Assisted On‐Chip Integration of Nanostructured α‐Quartz Microelectromechanical System

    30 March 2021 171 hit(s) Oxides
    The development of advanced piezoelectric α‐quartz microelectromechanical system (MEMS) for sensing and precise frequency control applications requires the nanostructuration and on‐chip integration of this material on silicon material.
  • Critical Effect of Bottom Electrode on Ferroelectricity of Epitaxial Hf0.5Zr0.5O2 Thin Films

    26 March 2021 198 hit(s) Oxides
    Epitaxial orthorhombic Hf0.5Zr0.5O2 (HZO) films on La0.67Sr0.33MnO3 (LSMO) electrodes show robust ferroelectricity, with high polarization, endurance and retention. However, no similar results have been achieved using other perovskite electrodes so far. Here, LSMO and other perovskite electrodes are compared.
  • Metallic Diluted Dimerization in VO2 Tweeds

    19 March 2021 217 hit(s) Oxides
    Though first order transitions are thought to be abrupt, materials find cunning ways to smooth the jump. Here we show that VO2 chooses making beautiful tapestries at the atomic scale. To see how, and how they affect its intriguing metal-insulator transition, continue reading:

INSTITUT DE CIÈNCIA DE MATERIALS DE BARCELONA, Copyright © 2020 ICMAB-CSIC | Privacy Policy | This email address is being protected from spambots. You need JavaScript enabled to view it.