| 摘要: | 本研究成功開發九個有機小分子之自組裝單層材料 (Self-Assembled Monolayers, SAM)，應用於鈣鈦礦太陽能電池中，這些材料可作為鈣鈦礦層與電荷傳輸層之間之界面修飾層(Interfacial Materials, IMs)，或直接作為電洞傳輸層(Hole Transporting Materials, HTMs)。
第一系列以具醛基之噻吩三苯胺 (TPAT)為核心，首先於其兩苯基末端接上拉電子基團五氟苯 (Pentafluorophenyl, FP)，之後於其噻吩之醛基接上四種不同之錨定基團:丙二腈 (Malononitrile, MN)、氰乙酸乙烯基 (Ethyl Cyanoacetate, CA)、氰甲基磷酸二乙酯 (Diethyl Cyanomethylphosphonate, PE)及氰甲基磷酸 (Cyanomethyl Phosphonic Acid, PA)，分子結構如下圖所示。目前TPAF-T-MN (1) 作為鉛鈣鈦礦太陽能電池之電洞界面修飾層，光電轉換效率 (PCE)為20.38%，元件效能優化中。
第二系列以環戊烷二噻吩(cyclopentadithiophene, CDT)為核心，引入不同鏈長之硫碳鏈，再於其末端接上兩種不同錨定基團:羧酸 (Carboxylic Acid, CA)及磷酸 (Phosphonic Acid, PA)，分子結構如下圖所示。此系列材料可作為電洞傳輸層，已應用於錫鈣鈦礦太陽能電池中，目前CDTSBr-CA (5)具7.2%PCE、CDTSBr-BA (6)具4.63% PCE、CDTSBr-PA (7)具2.18% PCE。CDTSFP-BA (9)作為電子界面修飾層，效率可達6%。
上述兩系列材料，皆已完成NMR與質譜分析鑑定結構，其中TPAF-T-MN (1)已經由SXRD進行單晶結構之解析。利用UV-vis和DPV評估其光學與電化學特性，從中測得了HOMO、LUMO及Eg等相關數據，並藉由TGA和DSC檢測材料之熱穩定性。
;In this thesis, nine self-assembled monolayer (SAM) materials were successfully developed and applied in perovskite solar cells. These materials could be employed as interfacial materials (IMs) or hole transporting materials (HTMs). Two new series of SAMs were developed based on thiophene–triphenylamine (TPAT) and cyclopentadithiophene (CDT) which bear different kinds of anchoring groups.
The first series of compounds is based on a thiophene–triphenylamine (TPAT) core bearing an aldehyde group. First, the phenyl ends of TPAT were introduced with electron-withdrawing pentafluorophenyl group (FP). Then, the aldehyde group on the thiophene unit was functionalized with four different anchoring groups, including malononitrile (MN), ethyl cyanoacetate (CA), diethyl cyanomethylphosphonate (PE), and cyanomethyl phosphonic acid (PA) to give four HTIMs, TPAF-T-MN (1), TPAF-T-CA (2), TPAF-T-PE (3), and TPAF-T-PA (4), respectly. Currently, TPAF-T-MN (1) as hole transporting interfacial material (HTIM) achieved power conversion efficiency (PCE) of 20.38% in lead-based perovskite solar cells (Pb-PSC). TPAF-T-CA (2), TPAF-T-PE (3), and TPAF-T-PA (4) are undergoing device testing.
The second series of compounds is based on a cyclopentadithiophene core bearing two different chain length of S-alkyl chains (CDTS). First, the thiophene end of CDTS was functionalized with two different units, including (1) a bromine atom (Br), which is capable of passivating defects; (2) an electron-withdrawing pentafluorophenyl group (FP). Then the S-alkyl chains end of CDTS was anchored with carboxylic acid (CA) or phosphonic acid (PA) to give four HTMs and one interfacial material, CDTSBr-CA (5), CDTSBr-BA (6), CDTSBr-PA (7), CDTSBr-PA-4 (8), and CDTSFP-BA (9). Currently, when applied as HTM in tin-based perovskite solar cells (Sn-PSC), CDTSBr-CA (5), CDTSBr-BA (6), and CDTSBr-PA (7) achieved PCEs of 7.2%, 4.63%, and 2.18%. In contrast, CDTSFP-BA (9) was applied as an electron transporting interfacial material (ETIM) and achieved 6% PCE in Sn-PSC. CDTSBr-PA-4 (8) is undergoing device testing.
The structures of all synthesized materials were confirmed by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The single-crystal structure of TPAF-T-MN (1) has been resolved via single crystal X-Ray diffractometer (SXRD). Their optical and electrochemical properties were analyzed using ultraviolet–visible spectroscopy (UV-vis) and differential pulse voltammetry (DPV). In addition, thermal stability was verified by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Device optimization of these new materials is currently in progress. |
