Department of Energy Engineering, Ulsan National Institute of Science and Technology (UNIST) , Ulsan 44919, South Korea.
Department of Chemical Engineering, Wonkwang University , Iksan, 54538, South Korea.
Nano Lett. 2017 Oct 11;17(10):6385-6390. doi: 10.1021/acs.nanolett.7b03225. Epub 2017 Sep 14.
Edged-selectively fluorine (F) functionalized graphene nanoplatelets (EFGnPs-F) with a p-i-n structure of perovskite solar cells achieved 82% stability relative to initial performance over 30 days of air exposure without encapsulation. The enhanced stability stems from F-substitution on EFGnPs; fluorocarbons such as polytetrafluoroethylene are well-known for their superhydrophobic properties and being impervious to chemical degradation. These hydrophobic moieties tightly protect perovskite layers from air degradation. To directly compare the effect of similar hydrophilic graphene layers, edge-selectively hydrogen functionalized graphene nanoplatelet (EFGnPs-H) treated devices were tested under the same conditions. Like the pristine MAPbI perovskite devices, EFGnPs-H treated devices were completely degraded after 10 days. The hydrophobic properties of EFGnPs-F were characterized by contact angle measurement. The test results showed great water repellency compared to pristine perovskite films or EFGnPs-H coated films. This resulted in highly air-stable p-i-n perovskite solar cells.
具有钙钛矿太阳能电池的 p-i-n 结构的边缘选择性氟化石墨烯纳米片（EFGnPs-F）在未封装的情况下，在暴露于空气中 30 天的时间里，相对于初始性能，稳定性提高了 82%。稳定性的提高源于 EFGnPs 上的 F 取代；聚四氟乙烯等氟碳化合物因其超疏水性和抗化学降解性而闻名。这些疏水性基团紧密保护钙钛矿层免受空气降解。为了直接比较类似亲水石墨烯层的效果，在相同条件下测试了边缘选择性氢化石墨烯纳米片（EFGnPs-H）处理的器件。与原始的 MAPbI 钙钛矿器件一样，EFGnPs-H 处理的器件在 10 天后完全降解。通过接触角测量对 EFGnPs-F 的疏水性进行了表征。测试结果表明，与原始钙钛矿薄膜或 EFGnPs-H 涂层薄膜相比，EFGnPs-F 具有优异的拒水性。这导致了高度稳定的 p-i-n 钙钛矿太阳能电池。
