以分子界面工程提升高分子及鈣鈦礦太陽能電池效能

Abstract

在本研究中，我們報告分子界面工程分別在高分子太陽能電池和鈣鈦礦太陽能電池中的應用。界面層具有改變電極工函數的作用，及可有效的提取激子和改變基板的表面能狀態，從而優化高分子太陽能電池中的異質接面形態。首先，具有官能基團的小分子可形成交聯網絡，提供長期熱穩定形態於高分子太陽能電池。其次，高分子太陽能電池之主動層與將金屬材料分散在電洞傳輸層中之界面層，由於局部表面電漿共振模式的激發，導致光學吸收的顯著增強。除此之外，將少量的乙基碘化銨（EAI）摻入鈣鈦礦前驅液中。對於乙基碘化銨衍生鈣鈦礦薄膜，觀察到在更高波長和更高結晶度下更強的吸光度，這兩者都與鈣鈦礦（MAPbI3-xClx）薄膜的更高表面覆蓋率相關。此外利用胺基寡分子通過氮原子和欠配位鉛（Pb2+）離子之間的配位鍵合來鈍化鈣鈦礦（MAPbI3）的缺陷位點。最後與優化前的元件相比，在分子界面工程的修飾下，光電轉換效率顯著提升（AM 1.5G 1000W m-2）。

In this study, we report molecular interfacial engineering for applications in polymer and perovskite solar cells. The Interfacial layer played the role of altering the working function of the electrodes for efficient carrier extraction, and changing the surface energy status of the substrate for optimizing the bulk heterojunction(BHJ) morphology in polymer solar cells. First, small molecules with functional groups were utilized to induce crosslinking networks, providing a long-term thermally stable morphology for polymer solar cell applications. Subsequently, the metallic materials were dispersed in the photoactive layer in the hole transporting layer, and between the interfacing layers of polymer solar cells, leading to significant enhancement in optical absorption as a result of the excitation of localized surface plasmon resonance. Apart from that, a small amount of ethylammonium iodide (EAI) was incorporated into the perovskite precursor solution. For our EAI-derived films, we observed stronger absorbances at higher wavelengths and higher degrees of crystallinity, both of which were associated with the higher surface coverage of the perovskite(MAPbI3-xClx) films. Furthermore, the amine-based oligomers were utilized to passivate the defect sites of perovskite(MAPbI3) through coordinated bonding between the nitrogen atoms and under-coordinated lead (Pb2+) ions. Finally, we obtained an improvement in power conversion efficiency (AM 1.5G 1000W m-2) for the device in the presence of molecular interfacial engineering, when compared with the pre-optimized devices.