为了钝化钙钛矿表面的缺陷、改善PCBM溶液的粘度和成膜性以达到优化器件性能的目的, 通过引入非富勒烯小分子(ITIC)和富电子聚合物(PVK)共掺杂修饰PCBM薄膜。结果表明: 通过调节ITIC的含量可以优化界面形貌, 提高器件的性能。当ITIC的质量分数为6%时, 获得了最优的器件性能。相比于纯PCBM的器件效率由5.26%提高到9.93%, 器件没有回滞现象。ITIC和PVK的引入提高了PCBM的成膜性能。此外, 还可以钝化钙钛矿表面的缺陷。这种协同作用有利于电荷传输和分离。综上所述, PVK和ITIC的加入抑制了大气中的水分和氧气, 提高了器件的稳定性。

In order to passivate the defects of the perovskite surface and improve the viscosity and film-forming properties of the PCBM solution so as to enhance the performance of device, the non-fullerene acceptor molecules(ITIC) and electron-rich poly(n-vinylcarbazole) (PVK) are used as additives of PCBM film. As a result, the interface morphology and the performance of PCBM are optimized by adjusting the content of ITIC and PVK. The optimal device is obtained when the ITIC content is 6%(mass fraction). Compared with the control device without additives, the power conversion efficiency(PCE) is increased from 5.26% to 9.93%, with no hysteresis. It is found that the introduction of ITIC and PVK improves the film-forming properties of PCBM. Moreover, the surface defect state of perovskite is passivated. The synergy is beneficial to the charge transport and separation. In summary, the addition of PVK and ITIC inhibits the moisture and oxygen in the atmosphere into the device and improves the stability of the device.