氧化锌具有良好电子传输性和高透光性,ZnO作为电子传输层已被广泛应用于聚合物太阳能电池。但采用溶胶凝胶法和真空镀膜制备ZnO电子传输层,因ZnO界面具有大量缺陷,极大增加载流子复合。抑制ZnO界面复合电流和改善ZnO界面接触性能,是提高ZnO基电子传输层聚合物太阳能电池性能关键所在。基于P3HT:PCBM反转型聚合物太阳能电池,采用磁控溅射ZnO层,研究了离子液功能化碳纳米粒子(ILCNs)修饰层或Ar/O2混合气体溅射沉积ZnO修饰层,以及Ar/O2溅射ZnO界面层与ILCNs联合修饰ZnO界面的聚合物太阳能电池性能。纯Ar和Ar/O2混合气体下一步溅射沉积ZnO电子传输层,其电池效率分别为2.2%和2.8%。经ILCNs修饰或Ar/O2溅射ZnO修饰层,电池效率分别达到3.4%和3.1%,并且分步溅射ZnO层并联合ILCNs修饰ZnO界面,聚合物太阳能电池效率可提高到3.8%。ZnO修饰型聚合物太阳能电池克服了电化学阻抗负阻效应,降低了反向暗电流并显示出更好的整流特性。研究表明,采用ILCNs修饰ZnO层和分步溅射ZnO层能有效抑制ZnO界面缺陷和改善界面接触性能,而采用分步溅射ZnO层与ILCNs联合修饰ZnO界面,这种联合修饰ZnO界面方案,更能增强ZnO层电子传输和提取能力,是提高聚合物太阳能电池效率更为有效方案。
Polymer solar cells(PSCs)with ZnO electron transporting layer has been widely studied because ZnO has superior electron transport capability and high light transmittivity.However,lots of defects existed in ZnO film fabricated with sol-gel method and vacuum sputtering deposition can greatly increase carrier recombination at the ZnO interface.Therefore,it is important to enhance the performance of PSCs to inhibit defects and improve contact quality of ZnO interface.The regioregular poly(3-hexylthiophene)(P3HT)and 6,6-phenyl C61-butyric acid methylester(PCBM)based inverted PSCs with ZnO electron transporting layer have been developed by using layered magnetron sputtered ZnO and/or ionic liquid functionalized carbon nanopartilces(ILCNs)modification.The power conversion efficiencies(PCEs)of PSCs with ZnO layer sputtered with Ar and Ar/O2 gas are2.2% and 2.8%,respectively.PSCs modified with ILCNs or layered sputtered ZnO can respectively reach 3.4% and 3.1%,and further up to 3.8% using layered sputtered ZnO and ILCNs integrated modification.PSCs using modified ZnO layer show the vanishment of negative capacitive behavior,lowering reverse dark current and better diode characteristics.The results indicated that using layered sputtered ZnO or ILCNs,or both integrated modification can efficiently inhibit the defects of ZnO interface and improve contact quality ZnO/P3HT∶PCBM interface.However,this integrated modification method is a more efficient strategy to enhance ZnO layer electron transporting and extraction capabilities,and further improve PCEs of PSCs.