Rare earth ions possess highly conductive, magnetic, electrochemical and luminescent properties, multiple valence electrons and long lifetime of excited state, thus could be alternatives as dopant to tune and promote the cathode interlayer property in solar cells. In this work, we study the modification of cathode interlayer by rare earth ion doping, based on the model of Yb doped ZnO by sol-gel method. A relative low doping concentration (below 1%) can improve the electron transport of ZnO and the solar cell performance. This is also confirmed by the obtained photocurrent density, excitons generation rate and electron mobility of device. The best PCE 11.04% (with V_OC 0.940 V, J_SC 16.58 mW cm⁻², FF 70.7%) is achieved with 0.5% Yb doping, based on PBDB-T:IT-M active layer, compared to the reference PCE of 10.19% with pure ZnO ETL. While with concentration over 1%, the Yb doping decreases the device performance.

稀土离子具有高导电，磁性，电化学和发光特性，具有多个价电子，并且具有长的激发态寿命，因此可以作为掺杂剂的替代品，以调节和促进太阳能电池的阴极层间性能。在这项工作中，我们基于溶胶-凝胶法掺Yb的ZnO模型，研究了稀土离子掺杂对阴极夹层的改性。相对较低的掺杂浓度（低于1％）可以改善ZnO的电子传输和太阳能电池的性能。所获得的光电流密度，激子产生速率和器件的电子迁移率也证实了这一点。最佳PCE 11.04％（V _OC为0.940 V，J _SC为16.58 mW cm ^-2，基于PBDB-T：IT-M有源层，采用0.5％的Yb掺杂可实现FF 70.7％），相比之下，纯ZnO ETL的参考PCE为10.19％。当浓度超过1％时，Yb掺杂会降低器件性能。