The design and development of a charge carrier transport material are decisive parameters for controlling the organic solar cell's power conversion efficiency (PCE). ZnO is one of the most suitable electron transport materials used in inverted bulk heterojunction polymer solar cells. However, the solution‐processed ZnO has surface defects, which hinders the power conversation efficiency of the device. Herein, it is designed and demonstrated that the 2D NO₂ group functionalized reduced graphene oxide (rGN) sheet coated on top of the 1D ZnO nanoridges not only passivates the surface but also enhances the charge transport property of the electron transport layer (ETL), thereby improving the overall PCE by 31%. Atomic force microscopy (AFM), field emission scanning electron microscopy (FESEM), and optical measurements reveal that the highly transparent bilayer ZnO/rGN ETL has uniform film formation and, thereby, improved ohmic contact between the cathode and the photoactive layer. Due to the improved electron transport from the photoanode (PTB7‐Th:PC₇₁BM) to the buffer layer, a photoinduced current density of 20.05 mA cm⁻² is achieved. This interface modification by rGN can be an effective strategy to passivate the surface and retards the recombination rate to enhance the efficiency of organic photovoltaic cells.

中文翻译：

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倒置有机太阳能电池表面空洞的同时钝化和ZnO电子传输层电荷转移性能的增强

电荷载流子传输材料的设计和开发是控制有机太阳能电池的功率转换效率（PCE）的决定性参数。ZnO是用于反向本体异质结聚合物太阳能电池的最合适的电子传输材料之一。但是，固溶处理的ZnO具有表面缺陷，这会妨碍器件的功率转换效率。在此，设计并演示了2D NO ₂在1D ZnO纳米脊顶部涂覆的基团官能化还原氧化石墨烯（rGN）片材不仅钝化了表面，而且还增强了电子传输层（ETL）的电荷传输性能，从而使整体PCE提高了31％。原子力显微镜（AFM），场发射扫描电子显微镜（FESEM）和光学测量表明，高透明双层ZnO / rGN ETL具有均匀的膜形成，从而改善了阴极和光敏层之间的欧姆接触。由于改善了从光电阳极（PTB7-Th：PC ₇₁ BM）到缓冲层的电子传输，光感应电流密度为20.05 mA cm ^-2已完成。通过rGN进行的这种界面修饰可以成为钝化表面并延迟重组速率以提高有机光伏电池效率的有效策略。