| 초록 |
Polymer solar cells (PSCs) have drawn attention owing to their potentials. The performance of PSCs is dependent on active layer and interfacial engineering between layers. Here, Ir(III) complex with small pendant cations was applied as an electron transport layer (ETL) to prove the charge accumulation effect and the performance of Ir based ETL delivered corresponding performance of ZnO based device. Furthermore, ZnO-Ir bilayer system boost up the performance. In addition, we found that energy level of metal based ETL that contacted with Ir(III) complexes shifted dependent on the ionic mobility of pendant cations(Li, Na, and K). More importantly, not only the enhancement PCE, but the devices with Ir(III) complexes exhibited high photo-stability. Under UV irradiation for 24 hours, the device with Ir(III) complexes retained ~70% of their original efficiency due to efficiently UV absorption of ETL, but the control devices dramatically reduced the PCE into ~50% under UV irradiation. |
