MOE Key Laboratory of Low-grade Energy Utilization Technologies and Systems, CQU-NUS Renewable Energy Materials & Devices Joint Laboratory, School of Energy & Power Engineering , Chongqing University , Chongqing 400044 , China.
Organic Semiconductor Research Center , Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences , Chongqing 400714 , China.
ACS Appl Mater Interfaces. 2018 Nov 21;10(46):39962-39969. doi: 10.1021/acsami.8b14224. Epub 2018 Nov 7.
ZnO is a widely used electron transport material in third generation solar cells. Intrinsic defects arising from different synthetic methods and conditions lead to different fluorescent colors. The defect mechanisms have been explored in the literature, but their impact on organic photovoltaic (OPV) cell performance is rarely reported. Herein, three different ZnO nanoparticles showing blue, green, and yellow emission colors are synthesized and incorporated into OPV cells. The as-cast ZnO films result in vastly different OPV performances. It is found the sodium acetate as the byproduct of the synthesis can significantly influence the interfacial contact. After removing the impurity via rinsing with polar organic solvents, the different ZnO nanoparticles can deliver similar power conversion efficiencies (PCEs) in three representative OPV systems. The PCEs reached 4, 8, and 10% in P3HT:PCBM-, PTB7-Th:PCBM-, and PBDB-T-SF:IT-4F-based OPV cells, respectively. A series of characterizations indicate that the intrinsic defect types do not affect the optical and electrical properties of the ZnO film, including photon transmittance, electrical conductivity, and charge extraction from the active layer as well as electron mobility. The results together suggest that the intrinsic defect in ZnO nanoparticles has little impact on OPV performance. Thus, it might be necessary to revisit the strategies for defect engineering or passivation in oxide-based interfacial materials.
氧化锌是第三代太阳能电池中广泛使用的电子传输材料。不同合成方法和条件下产生的本征缺陷导致了不同的荧光颜色。文献中已经探索了缺陷机制，但它们对有机光伏 (OPV) 电池性能的影响很少有报道。在此，合成了三种具有蓝色、绿色和黄色发射颜色的不同氧化锌纳米粒子，并将其掺入到 OPV 电池中。所得的氧化锌薄膜具有截然不同的 OPV 性能。研究发现，作为合成副产物的醋酸钠可以显著影响界面接触。通过用极性有机溶剂冲洗去除杂质后，不同的氧化锌纳米粒子在三种典型的 OPV 体系中可以提供相似的功率转换效率 (PCE)。在 P3HT:PCBM-、PTB7-Th:PCBM-和 PBDB-T-SF:IT-4F 基 OPV 电池中，PCE 分别达到了 4%、8%和 10%。一系列的表征表明，本征缺陷类型不会影响 ZnO 薄膜的光学和电学性质，包括光子透过率、电导率以及从活性层提取的电荷和电子迁移率。结果表明，氧化锌纳米粒子中的本征缺陷对 OPV 性能的影响很小。因此，有必要重新审视氧化物基界面材料中的缺陷工程或钝化策略。
