The performances of the organic solar cells (OSCs) largely depends on the selection and preparation of the electron transport layer (ETL). In this paper, the uniform and compact Ge nanoparticles (NPs) film was fabricated by using the plasma enhanced chemical vapor deposition (PECVD) method at room temperature. The Ge NPs film is formed by close packing of amorphous Ge particles with an average diameter of 6.05 nm, and the film shows a fairly smooth surface with a root-mean-square (RMS) roughness of 0.6419 nm. The results shows that Ge NPs film exhibits n-type characteristics, and the longitudinal conductivity of the film is 1.90 × 10⁻⁵ S/cm, which is better than that of the ZnO NPs film. The excellent longitudinal charge transport characteristics is attributed to the existence of the columnar structures in the Ge NPs. In addition, the Ge NPs film shows a visible light transmittance comparable to that of the ZnO NPs film. More importantly, the energy levels of the Ge NPs film meets the requirements of the PTB7:PC₇₀BM OSCs for the ETL, and the devices with the Ge NPs ETL shows the power conversion efficiency (PCE) of 7.38%. The characteristic of room temperature preparation make the Ge NPs ETL may become a reliable choice for the flexible devices in the near future.

有机太阳能电池 (OSC) 的性能很大程度上取决于电子传输层 (ETL) 的选择和制备。在本文中，采用等离子体增强化学气相沉积（PECVD）方法在室温下制备了均匀致密的锗纳米颗粒（NPs）薄膜。Ge NPs 薄膜由平均直径为 6.05 nm 的非晶 Ge 颗粒紧密堆积而成，薄膜表面相当光滑，均方根 (RMS) 粗糙度为 0.6419 nm。结果表明，Ge NPs薄膜呈现n型特性，薄膜纵向电导率为1.90×10 ^-5S/cm，优于 ZnO NPs 薄膜。优异的纵向电荷传输特性归因于 Ge NPs 中柱状结构的存在。此外，Ge NPs 薄膜显示出与 ZnO NPs 薄膜相当的可见光透射率。更重要的是，Ge NPs 薄膜的能级满足 PTB7:PC ₇₀ BM OSCs对 ETL 的要求，具有 Ge NPs ETL 的器件的功率转换效率 (PCE) 为 7.38%。室温制备的特性使得Ge NPs ETL在不久的将来可能成为柔性器件的可靠选择。