| 摘要: | 本研究主要以雙噻吩並吡咯 (dithienopyrrole, DTP)與環戊烷二噻吩 (cyclopentadithiophene, CDT)作為核心，開發出一系列新型有機小分子材料，以自組裝形式 (self-assembled)應用於鈣鈦礦太陽能電池之電洞傳輸層或界面修飾層。
第一系列以DTP作為核心，一端接上含氟原子的三苯胺基團 (fluorinated triphenylamine, F-TPA)作為推電子基，利用氟原子的強電負度性質改善能接匹配度並鈍化鈣鈦礦層缺陷，另一端接上不同錨定基團：丙二腈 (malononitrile, MN)、氰乙酸乙烯基 (ethyl cyanoacetate, CA)、氰甲基膦酸二乙酯 (diethyl cyanomethylphosphonate, PE)及氰基膦酸 (cyano phosphonic acid, PA)作為拉電子基，開發出DTPF-MN (1)、DTPF-CA (2)、DTPF-PE (3)以及DTPF-PA (4)四種電洞傳輸層材料，並與未含氟TPA之DTP系列進行比較。結果如我們預期，含氟的DTPF系列之HOMO能階確實比DTP系列要低。目前，DTPF-CA (2)應用於鉛-鈣鈦礦太陽能電池光電轉換效率 (PCE)達19.3%，並於無NiOx的Si-TOPCon/perovskite串聯電池中展現超過28%PCE，目前元件效能優化中。
第二系列以X-shaped DPCDT為核心，首先將其噻吩端官能基化，引入三種不同單元，包括 (1)含氟之推電子基團F-TPA、(2)具鈍化鈣鈦礦層缺陷之溴原子 (Br)、(3)具拉電子基團之五氟苯 (pentafluorophenyl, FP)，之後於苯環端接上錨定基團-丙二腈 (MN)或氰甲基膦酸二乙酯 (PE)，共開發出六種界面修飾層材料：DPCDTF-MN (5)、DPCDTF-PE (6)、DBrCDT-MN (7)、DBrCDT-PE (8)、DFPCDT-MN (9)及DFPCDT-PE (10)，目前元件效能測試中。
所有材料均由NMR與MS完成結構鑒定，藉由量測DPV及UV-Vis探討材料之電化學及光學性能 (HOMO/LUMO與Eg)，並利用DSC和TGA證實材料具有良好的熱穩定性，這些新型材料正在進行元件測試中。
;This study focused on developing a series of novel organic materials based on dithienopyrrole (DTP) and cyclopentadithiophene (CDT), which are designed for self-assembled applications as the hole transporting marerials (HTM) or interfacial marerials (IM) for perovskite solar cells (PSC).
First, DTP core was first connected to fluorinated triphenylamine (F-TPA) electron-donating group. The strong electronegativity of the fluorine is capable of lowering the HOMO energy level to better match the perovskite layer and passivate defects. Then, the other end of DTP core was connected to four different kinds of anchoring groups, namely malononitrile (MN), ethyl cyanoacetate (CA), diethyl cyanomethyl phosphonate (PE) and cyano phosphonic acid (PA) to give four HTMs; DTPF-MN (1), DTPF-CA (2), DTPF-PE (3) and DTPF-PA (4). A comparison was made with the non-fluorinated TPA series (DTP). As expected, with a fluorine addition in the TPA, the HOMO of the DTPF series indeed are lower than the non-fluorinated DTP series. Notably, DTPF-CA (2) achieved a high power conversion efficiency (PCE) of 19.3% in lead-perovskite solar cells, and exceeding 28% in NiOx-free TOPCon/ perovskite tandem cells. Device fabrication optimization is currently in progress.
The second series is based on X-shaped DPCDT. First, the thiophene end of DPCDT was functionalized with three different units, inclouding (1) a fluorinated electron-donating group, F-TPA; (2) a bromine atom (Br), which is capable of passivating defects; (3) an electron-withdrawing pentafluorophenyl group (FP). Then the phenyl end of DPCDT was anchored with malononitrile or diethyl cyanomethylphosphonate to give. six of interfacial materials: DPCDTF-MN (5), DPCDTF-PE (6), DBrCDT-MN (7), DBrCDT-PE (8), DFPCDT-MN (9) and DFPCDT-PE (10). The newly developed interfacial materials are currently undergoing device testing.
All of the materials were characterized by NMR and mass spectrometry, the electrochemical and optical properties of the materials, including HOMO / LUMO, energy levels and optical bandgap (Eg), were investigated by measuring differential pulse voltammetry (DPV) and UV–Vis spectroscopy. Thermal stability was evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), revealing good thermal resistance. |
