高電荷傳輸性質有機半導體分子之設計、合成及在有機電子元件應用

Design and Syntheses of Organicsemiconducting Molecules with High Charge Transporting Property for Application in Organic Electronics

特薩瑪(Samala Venkateswarlu)

指導教授 ： 陶雨台 ； 李積琛

國立交通大學/理學院/永續化學科技國際研究生博士學位學程/博士(2020年)

摘要

The polyheteroaromatics (PHs), including electron-rich polycyclic frameworks, display interesting set of properties such as optical, emissive, HOMO‒LUMO energy levels and others. Besides these properties, the packing motif within a crystal is another essential feature which influences the electronic coupling between neighbouring molecules. Correlation between chemical structures of PH systems with their properties including packing motifs, electronic coupling, and charge carrier mobility is always interesting and important. This perspective is crucial for the designing of new PH systems for many applications including organic electronics. For example, the electronic structure and molecular shape of PH molecules will determine the packing mode as cofacial, herringbone, lamellar, brick wall and other styles. These packing motifs relate to the electronic coupling, which is crucial to charge transporting. Contorted molecules have a high tendency to give cofacial-packing motif, and possibly high electronic coupling. In this regard, we are interested in contorted PHs involving thiophene unit. In particular, the design, synthesis, and characterizations of new thiophene-based contorted PHs as well as their potentials in field-effect transistor application and as hole transporting layers in perovskite solar cells. Furthermore, we are interested in embedding diacetylene units to the thiophene-based semiconductor BTBT, in order to prepare polydiacetylenes attached with crystalline BTBT for possible used in FET applications.
The two series of contorted, thiophene-based PHs are diphenanthro[9,10-b:9',10'-d]thiophene (DPT) and benzo[3,4]phenanthro[1,2-b]benzo[3,4]phenanthro[2,1-d]thiophene (BPBPT), both with polyarylthiophenes, as the central key precursors. The interesting part of this conversion was regioselective Scholl reactions, which selectively led to the desired DPT and BPBPT frameworks. NMR, high-resolution mass, techniques were used to characterize these phenathrothiophene and benzophenanthrothiophenes, while also the structural evidence for the proposed annulating patterns of DPT and BPBPTs came for the single-crystal analyses of the derivatives. The molecular structures of these DPTs and BPBPTs, as revealed by single-crystals X-ray analyses, include many fjords, which possibly allow these PHs to assemble in cofacial packing motifs. Single crystal-based transistors based on selected DPTs and BPBPTs single-crystals were fabricated and revealed that these materials are p-channel carriers. The best SCFET performance was measured from the single-crystals of benzophenathrothiophene, Flu-BPBPT, giving the highest mobility of 2.03 cm2V-1s-1,
For the synthesis of BPBT-cored diacetylenes, they were prepared from 2-alkyneBTBT with 1-bromoalkyne, using copper-catalyzed Sonogashira coupling reaction. The chemical structures of BTBT-diacetylenes were confirmed by NMR, and high-resolution mass analyses, along with photophysical measurements. These derivatives were subjected to UV-irradiation, with the idea that diacetylene units at the BTBT cores can undergo topochemical polymerization reactions to give conjugated polymer. The results showed that depend on the location of the diacetylene in the chain, an odd-even effect was observed.
On the other side, two donor–π–donor type (D–π–D) DPT derivatives with diphenanthrothiophene (DPT) as the central core carrying peripheral arylamino substituents, were synthesized using Suzuki coupling reactions between dibromo DPTs and triaryl amine boronate esters. Essential functional properties such as optical, thermal, energy level alignments, film morphologies, hole extraction ability, hole mobility and photovoltaic performance were measured showing the suitability of these two DPTs for PSC application. The best performance, with high power conversion efficiency (PCE) of 19.3%, was measured from a PSC device with the material as hole-transporting layer. This PCE value is higher than that obtained from the bench-mark HTM of Spiro-OMeTAD (PCE = 18.14%).

關鍵字

苯并噻吩 ； 苯并噻吩并噻吩 ； 肖尔反应 ； 半导体分子 ； 单晶场效应晶体管 ； 空穴传输材料

並列摘要

The polyheteroaromatics (PHs), including electron-rich polycyclic frameworks, display interesting set of properties such as optical, emissive, HOMO‒LUMO energy levels and others. Besides these properties, the packing motif within a crystal is another essential feature which influences the electronic coupling between neighbouring molecules. Correlation between chemical structures of PH systems with their properties including packing motifs, electronic coupling, and charge carrier mobility is always interesting and important. This perspective is crucial for the designing of new PH systems for many applications including organic electronics. For example, the electronic structure and molecular shape of PH molecules will determine the packing mode as cofacial, herringbone, lamellar, brick wall and other styles. These packing motifs relate to the electronic coupling, which is crucial to charge transporting. Contorted molecules have a high tendency to give cofacial-packing motif, and possibly high electronic coupling. In this regard, we are interested in contorted PHs involving thiophene unit. In particular, the design, synthesis, and characterizations of new thiophene-based contorted PHs as well as their potentials in field-effect transistor application and as hole transporting layers in perovskite solar cells. Furthermore, we are interested in embedding diacetylene units to the thiophene-based semiconductor BTBT, in order to prepare polydiacetylenes attached with crystalline BTBT for possible used in FET applications.
The two series of contorted, thiophene-based PHs are diphenanthro[9,10-b:9',10'-d]thiophene (DPT) and benzo[3,4]phenanthro[1,2-b]benzo[3,4]phenanthro[2,1-d]thiophene (BPBPT), both with polyarylthiophenes, as the central key precursors. The interesting part of this conversion was regioselective Scholl reactions, which selectively led to the desired DPT and BPBPT frameworks. NMR, high-resolution mass, techniques were used to characterize these phenathrothiophene and benzophenanthrothiophenes, while also the structural evidence for the proposed annulating patterns of DPT and BPBPTs came for the single-crystal analyses of the derivatives. The molecular structures of these DPTs and BPBPTs, as revealed by single-crystals X-ray analyses, include many fjords, which possibly allow these PHs to assemble in cofacial packing motifs. Single crystal-based transistors based on selected DPTs and BPBPTs single-crystals were fabricated and revealed that these materials are p-channel carriers. The best SCFET performance was measured from the single-crystals of benzophenathrothiophene, Flu-BPBPT, giving the highest mobility of 2.03 cm2V-1s-1,
For the synthesis of BPBT-cored diacetylenes, they were prepared from 2-alkyneBTBT with 1-bromoalkyne, using copper-catalyzed Sonogashira coupling reaction. The chemical structures of BTBT-diacetylenes were confirmed by NMR, and high-resolution mass analyses, along with photophysical measurements. These derivatives were subjected to UV-irradiation, with the idea that diacetylene units at the BTBT cores can undergo topochemical polymerization reactions to give conjugated polymer. The results showed that depend on the location of the diacetylene in the chain, an odd-even effect was observed.
On the other side, two donor–π–donor type (D–π–D) DPT derivatives with diphenanthrothiophene (DPT) as the central core carrying peripheral arylamino substituents, were synthesized using Suzuki coupling reactions between dibromo DPTs and triaryl amine boronate esters. Essential functional properties such as optical, thermal, energy level alignments, film morphologies, hole extraction ability, hole mobility and photovoltaic performance were measured showing the suitability of these two DPTs for PSC application. The best performance, with high power conversion efficiency (PCE) of 19.3%, was measured from a PSC device with the material as hole-transporting layer. This PCE value is higher than that obtained from the bench-mark HTM of Spiro-OMeTAD (PCE = 18.14%).

並列關鍵字

Phenanthrothiophenes ； Benzophenantrothiophenes ； Scholl reactions ； Semiconducting molecules ； Single crystal field-effect transistors ； Hole Transporting Materials

參考文獻

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