Semiconducting Materials Based on Donor/Acceptor Units for Optoelectronic Applications Teng Teng To cite this version: Teng Teng. Semiconducting Materials Based on Donor/Acceptor Units for Optoelectronic Appli- cations. Material chemistry. Sorbonne Université, 2018. English. NNT : 2018SORUS452. tel- 02966419 HAL Id: tel-02966419 https://tel.archives-ouvertes.fr/tel-02966419 Submitted on 14 Oct 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Sorbonne Université Ecole doctorale Physique et Chimie des Matériaux (ED397) Institut Parisien de Chimie Moléculaire (CNRS-UMR8232) Semiconducting Materials Based on Donor/Acceptor Units for Optoelectronic Applications Par Teng TENG Thèse de doctorat de Chimie Dirigée par Dr. David KREHER et Dr. Fabrice MATHEVET Présentée et soutenue publiquement le 12 octobre 2018 Devant un jury composé de: Directeur de Recherche CNRS Dr. Chantal ANDRAUD Rapporteur Université de Lyon Directeur de Recherche CNRS Dr. Philippe BLANCHARD Rapporteur Université d'Angers Professeur Prof. Anna PROUST Examinateur Sorbonne Université Chargé de Recherche CNRS Dr. Stéphane MERY Examinateur Université de Strasbourg Maître de Conference (HDR) Dr. David KREHER Directeur de thèse Sorbonne Université Chargé de Recherche CNRS Dr. Fabrice MATHEVET Co-Encadrant Sorbonne Université Glossary DMF N,N-Dimethylformamide DCM Dichloromethane THF Tetrahydrofuran PE Petroleum Ether PPh3 Triphenylphosphine EHA 2-Ethyl-1-hexylamine NBS N-Bromosuccinide OTS Octadecyltrichlorosilane Brine Saturated sodium chloride solution TMS Tetramethylsilane Ar Argon NMR Nuclear Magnetic Resonance UV Ultra-Violet DSC Differential Scanning Calorimetry POM Polarized Optical Microscopy OFET Organic Field Effect Transistor OLET Organic Light Emitting Field Effect Transistor OLED Organic Light Emitting Diodes OPV Organic Photovoltaics LCD Liquid-crystal display AFM Atomic-Forced Microscopy XRD X-ray diffraction TOF Time of flight BC Bottom-Contact TC Top-Contact MO Molecular Orbital theory HOMO Highest Occupied Molecular Orbital LUMO Lowest Unoccupied Molecular Orbital n-type Negative-type (electron-conducting) p-type Positive-type (hole-conducting) 3 nm nanometer LC Liquid Crystal M Mesophase Iso Isotropic phase Cr Crystalline phase Sm Smectic phase Nem Nematic phase Lam Lamellar mesophase (hearafter specifical definition in this thesis) LamA Smectic A-like lamellar mesophase HRMS High-resolution mass spectrometer 4 Content Glossary ............................................................................................................................. 3 Content .............................................................................................................................. 5 Chapter 1 Introduction ..................................................................................................... 9 1.1 Organic semiconductors .................................................................................................... 11 1.1.1 π-conjugated materials .................................................................................................. 11 1.1.1.1 π-conjugated polymers ........................................................................................................ 13 1.1.1.2 π-conjugated small molecules ............................................................................................. 14 1.1.2 Application of organic semiconductors ......................................................................... 14 1.1.2.1 OLEDs ............................................................................................................................... 15 1.1.2.2 OPVs ................................................................................................................................. 16 1.1.2.3 OFETs ................................................................................................................................ 18 1.1.3 Charge carrier mobility characterization methods .......................................................... 22 1.1.3.1 OFET ................................................................................................................................. 23 1.1.3.2 Time of flight (TOF) ........................................................................................................... 24 1.2 Liquid crystals ................................................................................................................... 25 1.2.1 Generalities .................................................................................................................. 25 1.2.2 Liquid crystals general classification ............................................................................. 26 1.2.2.1 Different types of mesogens ................................................................................................ 26 1.2.2.2 Different types of mesophases............................................................................................. 27 1.2.3 Liquid crystalline semiconductors ................................................................................ 33 1.2.4 Liquid crystalline fluorescent materials ......................................................................... 34 1.2.5 OLETs.......................................................................................................................... 35 1.2.6 Liquid crystalline materials characterization methods.................................................... 38 1.2.6.1 Polarizing microscope......................................................................................................... 38 1.2.6.2 Differential scanning calorimetry ........................................................................................ 39 1.2.6.3 X-ray diffraction ................................................................................................................. 40 1.3 Narrow bandgap materials ............................................................................................... 42 1.3.1 Generalities .................................................................................................................. 42 1.3.2 Design and synthesis of narrow bandgap materials ........................................................ 42 1.3.2.1 Synthetic Approaches ......................................................................................................... 42 1.3.2.2 Rational Design for Different Applications.......................................................................... 44 1.3.3 State of the art ............................................................................................................. 45 1.3.3.1 OPVs ................................................................................................................................. 45 1.3.3.2 Ambipolar OFETs .............................................................................................................. 49 1.4 Aim of work ....................................................................................................................... 54 5 Chapter 2 Synthesis and Characterization of Liquid Crystal Fluorescent Derivatives ............................................................................................................................................. 57 2.1 Synthesis ............................................................................................................................ 59 2.1.1 Synthesis of precursory building blocks ........................................................................ 59 2.1.2 Synthesis of target calamitic C10-PBT and C6-PBT ...................................................... 60 2.2 Photophysical properties (absorption and emission) ........................................................ 61 2.2.1 Absorption and emission of C10-PBT ........................................................................... 61 2.2.2 Absorption and Emission of C6-PBT ............................................................................ 64 2.3 Mesomorphic properties ................................................................................................... 65 2.3.1 DSC and POM of C10-PBT .......................................................................................... 66 2.3.2 DSC and POM of C6-PBT ............................................................................................ 67 2.4 Self-organization study (X-ray diffraction and Atomic force microscopy) ..................... 69 2.4.1 X-ray diffraction (XRD) ............................................................................................... 69 2.4.1.1 XRD of C10-PBT ............................................................................................................... 70 2.4.1.2 XRD of C6-PBT ................................................................................................................. 71 2.4.2 Atomic force microscopy (AFM) .................................................................................. 72 2.5