Synthesis of Crosslinkable Polyfluorenes, Hole- transporting and Electro-transporting Molecules and Their Applications on the PLED Devices

本研究成功合成出帶有oxetane官能基的oxadiazole (Oxa-oxe)和 triazole (Tri-oxe) 電子傳導分子、 triphenylamine (Tpa-Oxe) 電洞傳導分子及polyfluorene (P2)發光層材料，並且用H1-NMR, C13-NMR, IR, Mass 和 EA等儀器鑑定合成的結果。從Dsc圖譜得知，在Polyfluorene側鏈位置導入oxetane破壞了原本的結晶性，交聯過後P2的 Tg 比未交聯者高了十度。從交聯後溶解度測試得知，只有P2和Tpa-Oxe的薄膜可以交聯，而Oxa-Oxe,和Tri-Oxe電子傳導分子則無法交聯。根據CV量測所得的能階圖得知，Tpa-Oxe是一個好的電洞注入材料; Tri-Oxe 為一個好的擋電洞材料而Oxe-Oxe除了是一個好的電子注入材料同時也是一個好的擋電洞材料。初步測試，本實驗所製作的元件亮度介在58~330 Cd/m2之間而效率值介在0.05~2.69 Cd/A之間。利用將發光層交聯的方式作為元件，可以增加載子注入在發光層之後的穩定性，得到較多的激子及較高的光通量。從EL的圖譜得知，利用交聯過後的P2為發光材料，可以避免高分子鏈之間靠得太近而產生g 帶，即可得到較純的光色。In this research work, we have successfully synthesized the carrier-transporting materials containing the oxetane crosslinkable groups such as oxdiazole (Oxa-oxe), triazole (Tri-oxe) and triphenylamine (Tpa-oxe), and polyfluorene light emitting material containing the oxetane crosslinkable group (P2). From DSC results, we can clearly observe that the crystallinity of polyfluorene was reduced by incorporating the oxetane group into the side chain of polyfluorene, and the Tg of the Polyfluorene was increased from 25℃ to 35℃ after crosslinking. We also found that only the films of Tpa-Oxe and P2 can be crosslinked with the initiator of triarylsulfonium hexafluorophosphate, but the films of Tri-Oxe and Oxa-Oxe can’t. Based on the CV results, the hole injection properties of Tpa-Oxe materials was not significantly changed after crosslinking. Preliminary results also showed that the brightness of all the fabricated PLED devices was in a range of 58~330 Cd/m2 with the efficiency of 0.05~2.69 Cd/A. Due to the fact that Crosslinking can prevent the adjacent chain segments from quenching with each other and restrain the existence of the g band, it increase the number of excitons in P2 to emit light.Contents AbstractsⅠ 中文摘要Ⅱ ContentsⅢ List of Tables and SchemesⅧ List of Figures Ⅸ 1. Introduction 1 1.1. Foreword1 1.2. Principle of Emission and Structure of MLED 4 1.3. Paper Review 11 1.3.1. Oxadiazole derivatives 12 1.3.2. Triazole derivatives 16 1.3.3. Triphenylamine derivatives 19 1.3.4. Crosslinkable in MLED 22 1.4. Current Situation of Development for Industry regarding MLED26 1.5. Motivation of Experiments 30 2. Experimental Section 31 2.1. Chemicals and Instruments 2.1.1. Chemicals 31 2.1.2. Instruments 33 2.2. Synthesis 2.2.1. Synthesis of 2, 5-bis (4-(((3-methyloxetan-3-yl) methoxy)methyl) phenyl)-1,3,4-oxadiazole.(Oxa-Oxe) (1). Synthesis of (3-methyloxetan- 3-yl) methanol. (Oxe-OH) 36 (2). Synthesis of 2,5-dip-tolyl-1,3,4- oxadiazole. (Oxa -CH3) 37 (3). Synthesis of 2,5-bis(4-(bromomethyl) phenyl) -1,3,4 -oxadiazole. (Oxa-CH2Br) 37 (4). Synthesis of 2,5-bis(4-(((3-methyloxetan-3- yl) methoxy)methyl)phenyl)-1,3,4- oxadiazole.(Oxa-Ox-e)37 2.2.2. Synthesis of 3,5-bis(4-((3-methyloxetan-3-yl)methoxy) pheny- l)-4-phenyl-4H-1,2,4-triazole.(Tri-Oxe). (1). Synthesis of 3-(bromomethyl)-3 -methyl oxetane . (Oxe- Br) 39 (2). Synthesis of 4-(5-(4-hydroxyphenyl)-4-phenyl -4H- 1,2,4–triazol -3-yl )phenol.(Tri-OH) 40 (3). Synthesis of 3,5-bis(4-((3-methyloxetan-3-yl) methoxy) phenyl)-4-phenyl-4H-1,2,4-triazole. (Tri-Oxe) 40 2.2.3 Synthesis of N,N’-bis(4-(3-methyloxetan-3-yl)methoxy) phenyl)-N,N’ -diphenylbenzidine. (Tpa-Oxe). (1). Synthesis of 3-((4-bromobenzyloxy)methyl)-3-methyl- oxetane .(Br-Ben-Oxe) 42 (2). Synthesis of N,N’-bis(4-(3-methyloxetan-3-yl) metho- xy)phenyl) -N,N’-diphenylbenzidine. (Tpa-Oxe) 42 2.2.4. Synthesis of Monomer (1). Synthesis of 2,5-dibromobenzene -1,4-diol. (Ben- OH)45 (2). Synthesis of 1,4-dibromo-2,5-bis(hexyloxy) benzene- e.(Ben-Hex) 46 (3). Synthesis of 3-((6-bromohexyloxy)methyl) - 3-methyl oxetane.(Br-Hex-Oxe) 46 (4). Synthesis of 3-((6-(4-(6-((3-methyloxetan- 3-yl) methoxy)hexyloxy)-2,5- dibromophenoxy) hexyl-oxy)methyl)-3- methyloxetane.(Ben-Hex-Oxe)…47 (5). Synthesis of 2,7-Dibromofluorene (Br-Fluo) 47 (6). Synthesis of 2,7-Dibromo-9,9 dihexylfluorene (Hex-Fluo-Br) 48 (7). Synthesis of 2-(9,9-dihexyl-2-(4,4,5,5- tetramethyl -1,3,2-Dioxaborolan-2-yl)-9H-fl-uoren-7- yl)-4,4,5,5-tetramethyl-1,3,2- dioxaborolanev (Hex-Fluo-Boro) 48 2.2.5. Polymeriaztion 49 2.3. Characterization 2.3.1. NMR 50 2.3.2. FT-IR 50 2.3.3. EA 51 2.3.4. Mass51 2.3.5. GPC 51 2.3.6. Uv-vis51 2.3.7. PL 52 2.3.8. DSC 52 2.3.9. TGA 52 2.3.10 CV 52 2.3.11 I-V-L 53 2.4. Crosslink Procedure 54 2.4.1 Film state 54 2.4.2 Gelation test for P2 after crosslinking 54 2.5. Solvent resistibility test 54 3. Results and Discussion 56 3.1. Synthesis and Characterization 56 3.1.1. NMR (1). Oxa-Oxe.58 (2). Tri-Oxe.59 (3). Tpa-Oxe.59 (4). Monomers and Polymers 60 3.1.2. IR (1). Oxa-Oxe 62 (2). Tri-Oxe 62 (3). Tpa-Oxe 63 (4). Polymers 63 3.1.3. Mass 64 3.1.4. EA 64 3.1.5 Molecule Weight of P1 and P2 65 3.2. Spectroscopic Properties 65 3.3. Solvent resistibility test 67 3.4. Analysis of thermal property 68 3.4.1. TGA 69 3.4.2. DSC 69 3.5 Cyclic Voltammetry 70 3.6 EL and I-V-L 71 3.6.1 I-V-L 71 3.6.2 EL 73 4. Conclusions 75 5. References 113 List of Tables and Schemes Table.1 Advantages and disadvantages of all kind of flat- panel displays 1 Table.2 Advantages, disadvantages, and appropriate field for PLED or OLED 5 Table.3 The common materials for the electrode or emitting materials 6 Table.4 Companies which did the research regarding MLED 28 Table.5 Element Analysis of compounds 64 Table.6 Molecule weight of P1 and P2 65 Table.7 Configurations of the devices 72 Table.8 Configurations of the devices (including EIL) 72 Table.9 Performance of the device 73 Scheme 1 Synthesis of Oxa-Oxe 36 Scheme 2 Synthesis of Tri-Oxe 39 Scheme 3 Synthesis of Tpa-Oxe 42 Scheme 4 Synthesis of Monomers (Ⅰ) 44 Scheme 5 Synthesis of Monomers (Ⅱ) 45 Scheme 6 Synthesis of Polymers 49 List of Figures Fig.1 Configurations of MLED and LCD 3 Fig.2 Comparison of LCD and MLED 3 Fig.3 Basic configuration of MLED 4 Fig.4 Multi-layer device (ETL or EIL) 6 Fig.5 Multi-layer device (HTL or HIL) 6 Fig.6 Multi-layer device (HTL or HIL and ETL or EIL) 7 Fig.7 Energy state for single layer MLED (zero bias) 8 Fig.8 Energy state for single layer MLED (Forward Bias=Turn on voltage) 8 Fig.9 Energy state for single layer MLED (Forward Bias>Turn on voltage) 9 Fig.10 Energy state of Negative Polaron 9 Fig.11 Energy state of Positive Polaron 10 Fig.12 Energy state of Exciton 10 Fig.13 (a) oxadiazole polymer 1 (b) oxadiazole polymer 2 Fig.14 PPV containing pedant oxadiazole group 13 Fig.15 PPV containing electron-withdrawing groups 14 Fig.16 non-all conjugated polymer 15 Fig.17 PF-OXD 15 Fig.18 PPV-Derivatives 16 Fig.19 polymers containing electro-withdrawing groups 17 Fig.20 TRIDSB 18 Fig.21 PPV-containing triazole group 18 Fig.22 TAZ-MEH-PPV, TAZ-DBE-PPV 19 Fig.23 PPV containg triazole groups 19 Fig.24 Triarylamine-containing polyperfluorocycolbutanes 20 Fig.25 PTPAF 21 Fig.26 TPD-Si2 21 Fig.27 V-L Curve 21 Fig.28 triarylamine containing PFO-OXD polymer 22 Fig.29 Crosslink polymer 22 Fig.30 TPA-SIO3 24 Fig.31 crosslinked polymer 24 Fig.32 X-HTPA 25 Fig.33 Merchandises made by MLED (1) 27 Fig.34 Merchandises made by MLED (2) 28 Fig.35 Diagram of the device 53 Fig.36 H1-NMR of Oxe-OH 77 Fig.37 H1-NMR of Oxa-CH3 77 Fig.38 H1-NMR of Oxa-CH2Br 78 Fig.39 H1-NMR of Oxa-Oxe 78 Fig.40 C13-NMR of Oxa-Oxe 79 Fig.41 H1-NMR of Oxe-Br 79 Fig.42 H1-NMR of Tri-OH 80 Fig.43 H1-NMR of Tri-Oxe 80 Fig.44 H1-NMR of Br-Ben-Oxe 81 Fig.45 C13-NMR of Br-Ben-Oxe 81 Fig.46 H1-NMR of Tpa-Oxe 82 Fig.47 H1-NMR of Ben-OH 82 Fig.48 H1-NMR of Oxe-C6Br 83 Fig.49 H1-NMR of Ben-Hex 83 Fig.50 H1-NMR of Ben-Hex-Oxe 84 Fig.51 H1-NMR of Br-Fluo 84 Fig.52 H1-NMR of Br-Fluo-Hex 85 Fig.53 H1-NMR of Hex-Fluo-Boro 85 Fig.54 H1-NMR of P1 86 Fig.55 H1-NMR of P2 86 Fig.56 IR spectrum of Oxa-CH3 87 Fig.57 IR spectrum of Oxa-CH2Br 87 Fig.58 IR spectrum of Oxa-Oxe 88 Fig.59 IR spectrum of Tri-OH 88 Fig.60 IR spectrum of Tri-Oxe 89 Fig.61 IR spectrum of Tpa-Oxe 89 Fig.62 IR spectrum of P1 90 Fig.63 IR spectrum of P2 90 Fig.64 IR spectrum of P2-C 91 Fig.65 Mass Characterization of Oxa-Oxe 91 Fig.66 Mass Characterization of Tri-Oxe 92 Fig.67 Mass Characterization of Tpa-Oxe 92 Fig.68 Uv-vis spectrum of solution state for Oxa-Oxe 93 Fig.69 Uv-vis spectrum of solution state for Tri-Oxe 93 Fig.70 Uv-vis spectrum of solution state for Tpa-Oxe 94 Fig.71 PL spectrum of solution state for Oxa-Oxe 94 Fig.72 PL spectrum of solution state for Tpa-Oxe 95 Fig.73 PL spectrum of solution state for Tri-Oxe 95 Fig.74 Uv-vis, PL spectrum of solution and film state for Oxa-Oxe 96 Fig.75 Uv-vis, PL spectrum of solution and film state for Tri-Oxe 96 Fig.76 Uv-vis, PL spectrum of solution and film state for Tpa-Oxe 97 Fig.77 Uv-vis spectrum of solution state for initiator 97 Fig.78 Uv-vis, PL spectrum of solution and film state for P1 98 Fig.79 Uv-vis, PL spectrum of solution and film state for P2 98 Fig.80 Uv-vis spectrum of film state for Tpa-Oxe 99 Fig.81 Uv-vis spectrum of film state for P2 99 Fig.82 Uv-vis spectrum of film state for Tri-Oxe 100 Fig.83 Uv-vis spectrum of film state for Oxa-Oxe. 100 Fig.84 Solubility test for Tpa-Oxe 101 Fig.85 Solubility test for P2 101 Fig.86 TGA of P1 with a heating rate of 10℃/min 102 Fig.87 TGA of P2 with a heating rate of 10℃/min 102 Fig.88 TGA of P2-C with a heating rate of 10℃/min. 103 Fig.89 DSC of P1 with a heating rate of 10℃/min for the second run.103 Fig.90 DSC of P2 (1) with a heating rate of 10℃/min for the second run 104 Fig.91 DSC of P2 (2) with a heating rate of 10℃/min for the second run 104 Fig.92 DSC of P2-C with a heating rate of 10℃/min for the second run 105 Fig.93 CV of Ferrocene in 0.1 M N-Bu4NClO4 with Scan Rate of 20 mv/s 105 Fig.94 CV of Oxa-Oxe in 0.1 M N-Bu4NClO4 with Scan Rate of 20 mv/s 106 Fig.95 CV of Tri-Oxe in 0.1 M N-Bu4NClO4 with Scan Rate of 20 mv/s 106 Fig.96 CV of Tpa-Oxe in 0.1 M N-Bu4NClO4 with Scan Rate of 20 mv/s 107 Fig.97 CV of P1 in 0.1 M N-Bu4NClO4 with Scan Rate of 20 mv/s 107 Fig.98 CV of P2 in 0.1 M N-Bu4NClO4 with Scan Rate of 20 mv/s 108 Fig.99 CV of Crosslinked Tpa-Oxe in 0.1 M N-Bu4NClO4 with Scan Rate of 20 mv/s 108 Fig.100 CV of P2-C in 0.1 M N-Bu4NClO4 with Scan Rate of 20 mv/s 109 Fig.101 The relative energy diagram for these materials with electrode 109 Fig.102 I-V of the deivces 110 Fig.103 V-L of the deivces 110 Fig.104 Efficiency of the deivces 111 Fig.105 EL of the devices 111 Fig.106 CIE Chromaticity Diagrams of the devices 11