本研究以實驗室先前利用CDT (cyclopentadithiophene)單元所開發之多併環材料: DCDTT (dicyclopentadithienothiophene)與多環材料: BCDT (bicyclopentadithiophene)作為核心，多環噻吩之核心有助於電荷轉移進而增加載子移動率，並於多環的核心架構中引入分支的碳鏈以增進分子溶解度，透過在結構末端接上具有雙氟原子的茚酮 (fluorinated indanone, INF)分子，製備出兩種結構相似的化合物: INF-DCDTT與INF-BCDT。相比於其他鹵素元素，具有雙氟原子的茚酮溶解度更佳，有助於提高分子的溶解度，使元件製備成膜能較為平整不堆疊，利於探討元件所得之光伏參數。 本研究開發之化合物，除了能作為非富勒烯受體(non-fullerene acceptors, NFAs)應用於有機太陽能電池(Organic Solar Cell, OPV)中，亦能作為鈣鈦礦電池(perovskite solar cells, PSCs)的添加劑使用，透過末端的羰基與修飾的二氰乙烯基去鈍化鈣鈦礦電池的表面缺陷，能有助於提高元件效能，本實驗室於2022年四月發表至JMCA的文獻研究中，利用INCl-DCDTT作為鈣鈦礦層之添加劑，能有效提高電池效能從原先17%至21.39%，因此本研究使用拉電性更強且溶解度更好的雙氟茚酮，期望能獲得更好的元件效能。這些材料皆完成NMR與質譜之結構鑒定，並利用UV-vis 及 DPV測量其光學及電化學性質(HOMO、LUMO與Eg)，再藉由 DSC 及 TGA 測量其材料熱穩定性，這些新開發的有機光電材料正進行相關元件測試，期望有良好的效能表現。 ;DCDTT (Dicyclopentadithienothiophene) and BCDT (bicyclopentadithiophene) are two organic optoelectronic materials that are derived from the CDT (cyclopentadithiophene) unit. The core of the CDT helps with charge transfer and increases the carrier mobility. Introducing branched carbon chains into the core structure of the CDT enhances the molecular solubility. Both of two compounds were end-capped with the same electron withdrawing group, fluorinated dicyanomethylene indanone (INF). Via Knoevenagel condensation, two similar materials were obtained, INF-DCDTT and INF-BCDT. Additionally, compared to other halogen elements, indanones with difluorine atoms have better solubility, which is essential for producing high-quality film in solar cell devices. These two compounds also can serve as additive in perovskite solar cells (PSCs). Our group has published a related study on JMCA in April, 2022. The presence of carbonyl (C=O) and cyano (C≡N) groups have a good interaction with undercoordinated Pb2+ ions and passivate the trap states in the perovskite films. Introducing INCI-DCDTT as a donor passivator into Pb-based PSCs increases the power conversion efficiency from 17% to 21.39% compared with devices without the additive. It is expected that INF-DCDTT can achieve better device performance by using stronger electron-withdrawing and better solubility difluorine atoms. The chemical structures of these newly developed materials were characterized by NMR spectroscopy and mass spectrometry. Furthermore, their optical properties were investigated using UV-vis spectroscopy, their electrochemical properties were analyzed by DPV, and their thermal stabilities were determined by DSC and TGA. Optoelectronic devices made from these newly developed small molecules are currently being optimized.
