有機電洞傳輸材料在鈣鈦礦太陽能電池元件中佔有非常重要的地位，但超過九成五以上的相關文獻幾乎都在探討元件界面效應、鈣鈦礦層種類、如何提昇光電轉換效率等等，很少有報導聚焦於電洞傳輸材料的新合成方法。傳統上，電洞傳輸材料合成必須仰賴Suzuki-或是Stille耦合反應，但這些反應需要預先製備空氣敏感的有機硼或是具有毒性的有機錫試劑。在本次計畫中，有別於傳統，我們提出了利用碳氫鍵活化反應當作合成有機小分子電洞傳輸材料的關鍵步驟，此類省步驟合成策略不需要有機硼或有機錫試劑, 大幅地縮短材料製程時間。藉由碳氫鍵活化反應，我們將設計與合成一系列直線型(對稱/非對稱)與星狀有機小分子，過程中我們將試著篩選出最佳化的反應參數/條件。我們也會對於這些小分子進行光物理、電化學、熱性質等等分析，並利用旋轉塗佈法把它們製作成鈣鈦礦太陽能電池元件中的電洞傳輸層，量測出光電轉換效率並檢驗這些有機小分子是否有機會成為免摻雜劑(dopant-free)的電洞傳輸材料。此外，為了取代相對昂貴的鈀催化劑，我們預計開發具有價格優勢的碳氫鍵活化合成方法學(銅、鈷、錳觸媒)，並應用於新型的有機小分子電洞傳輸材料的製備。 ;Hole-transporting materials (HTMs) play an important role in perovskite-based solar cells. We noticed that over 95% literatures focused mainly on the device/interface engineering, perovskite components, HTM molecule modifications, or PCE enhancements. Much less attention was paid on the development of efficient synthetic strategies for HTMs. Traditionally, accessing this class of compounds relied on Suzuki- or Stille cross-coupling reactions that required the preparation of air-sensitive organoborons or toxic organotin reagents. Therefore, in this proposal, we plan to facilely synthesize a series of small-molecule HTMs using C-H activation/arylation as key step thus reducing the material preparation time and chemical wastes. By means of the fully optimized reaction parameters, we propose to synthesize linear (symmetrical ones: D-pi-D & A-pi-A / unsymmetrical ones: D-pi-A) and star-shaped organic molecules. These molecules will be subject to the analysis of their optical, electrochemical, and thermal properties prior to the device fabrication and characterization of perovskite solar cells using them as hole-transport layers. More importantly, we will investigate if these small molecules could act as dopant-free HTMs. In addition, to replace the precious palladium catalysts, we propose to develop copper-, cobalt-, or manganese-catalyzed C-H activation/arylation reactions for the new HTMs synthesis. Bridging the step-economical C-H activation methodologies with organic HTMs preparations still remains less explored.
