Department of Flexible and Printable Electronics and LANL-CBNU Engineering Institute-Korea, Jeonbuk National University, 567, Baekje-daero, Deokjin-gu, Jeonju-si 54896, Jeollabuk-do, Republic of Korea.
Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Pune 411 008, India.
ACS Appl Mater Interfaces. 2023 Jun 21;15(24):29597-29608. doi: 10.1021/acsami.3c04852. Epub 2023 Jun 8.
Perovskite solar cells (PSCs) emerged as potential photovoltaic energy-generating devices developing in recent years because of their excellent photovoltaic properties and ease of processing. However, PSCs are still reporting efficiencies much lower than their theoretical limits owing to various losses caused by the charge transport layer and the perovskite. In this regard, herein, an interface engineering strategy using functional molecules and chemical bridges was applied to reduce the loss of the heterojunction electron transport layer. As a functional interface layer, ethylenediaminetetraacetic acid (EDTA) was introduced between PCBM and the ZnO layer, and as a result, EDTA simultaneously formed chemical bonds with PCBM and ZnO to serve as a chemical bridge connecting the two. DFT and chemical analyses revealed that EDTA can act as a chemical bridge between PCBM and ZnO, passivate defect sites, and improve charge transfer. Optoelectrical analysis proved that EDTA chemical bridge-mediated charge transfer (CBM-CT) provides more efficient interfacial charge transport by reducing trap-assisted recombination losses at ETL interfaces, thereby improving device performance. The PSC with EDTA chemical bridge-mediated heterojunction ETL exhibited a high PCE of 21.21%, almost no hysteresis, and excellent stability to both air and light.
钙钛矿太阳能电池（PSCs）因其优异的光伏性能和易于处理而成为近年来发展起来的潜在光伏能源产生器件。然而，由于电荷传输层和钙钛矿引起的各种损耗，PSCs 的效率仍然远远低于其理论极限。在这方面，本文应用了一种功能分子和化学桥的界面工程策略，以降低异质结电子传输层的损耗。作为一种功能界面层，乙二胺四乙酸（EDTA）被引入到 PCBM 和 ZnO 层之间，结果，EDTA 同时与 PCBM 和 ZnO 形成化学键，充当连接两者的化学桥。DFT 和化学分析表明，EDTA 可以在 PCBM 和 ZnO 之间充当化学桥，钝化缺陷部位，并改善电荷转移。光电分析证明，EDTA 化学桥介导的电荷转移（CBM-CT）通过减少 ETL 界面处的陷阱辅助复合损耗，提供了更有效的界面电荷传输，从而提高了器件性能。具有 EDTA 化学桥介导的异质结 ETL 的 PSC 表现出 21.21%的高光能量转换效率，几乎没有滞后现象，并且对空气和光都具有出色的稳定性。
