引入耐水性電子傳輸層及光活性層提升有機光伏的水下穩定性

10.29803/CE.202408_71(4).0008

張嘉富；謝丞典；林玠廷；闕居振

耐水電子傳輸層 ； 有機光伏器件 ； 耐水穩定性 ； nanoparticle TiO_2 ； organic photovoltaics ； underwater stability

化工

71卷4期（2024 / 08 / 01）

80 - 90

繁體中文;英文

我們經由挑選適當的耐水電子傳輸層與有機光活性層成功提升有機光伏器件（organic photovoltaics）的效率及水下穩定性。我們首先發現高分子間強大的纏結能力（entanglement）能使全聚合物體異質結（bulk heterojunction）在泡水後的薄膜形貌不會有太大的變化，展現良好的耐水穩定性。另一方面，我們發現納米顆粒等級的二氧化鈦（np-TiO_2）比常用的氧化鋅（ZnO）更適合做為耐水電子傳輸層（electron transport layer, ETL）並且其粗糙的表面可有效加強與光活性層之間的附著力，防止泡水後的薄膜物理分層。最後，我們證明np-TiO_2／全聚合物體異質結半電池在水浸泡下具有卓越的穩定性，泡水前後的薄膜形貌和電荷載流子轉移行為幾乎維持不變，最終使得衍生的全電池在泡水後的效率沒有太大變化。我們的結果清楚展示全聚合物體異質結和np-TiO_2 ETL這組合可成功地改善未封裝有機光伏器件在高濕度環境甚至水浸泡下的耐久性，有助於其未來水下應用的發展。

Water ingress is one of the major environmental stresses to cause the degradation of device performance in organic photovoltaic (OPVs) and is one of the major barriers impeding their commercialization. This work demonstrates that combining the use of a nanoparticle titanium dioxide (np-TiO_2) electron transporting layer (ETL) and an all-polymer bulk heterojunction (BHJ) photoactive layer can endow the derived OPV with a much better water resistivity than the commonly employed zinc oxide (ZnO) ETL or polymer:small molecule BHJ blends. Polymer donors/acceptors are first shown to possess better water-immersion than the small molecule counterparts. Hence, the all-polymer blend exhibits the lowest absorbance losses after water immersion among the studied BHJ systems. Furthermore, the result reveals that tailoring the structure of the TiO_2 ETL from planar to nanoparticles effectively strengthens the adhesion at the ETL/BHJ interface to prevent physical delamination. Finally, the np-TiO_2/all-polymer blend (half-cell) is demonstrated to have superior stability under water immersion, i.e., unchanged morphology and charge carrier transfer, as well as no efficiency changes in the complete cells. This work demonstrates the great potential of the all-polymer blends and np-TiO_2 ETL for improving the durability of unencapsulated OPVs under high humidity environments and even water immersion.