Yoon Tae Oh, Alam Shabaz, Baek Dohun, Lee Dongwoon, Na Hyemi, Cha Jeongbeom, Jin Haedam, Lee Myeoungwon, Li Meng Qian, Yang Seoju, Han Sanghun, Seo Gayoung, Choi Jongmin, Jang Jaeyoung, Lee Jaewon, Kim Min
School of Chemical Engineering, Jeonbuk National University, Jeonju, 54896, Republic of Korea.
Department of Chemical Engineering and Applied Chemistry, Chungnam National University, Daejeon, 34134, South Korea.
Small. 2025 Oct;21(39):e2504757. doi: 10.1002/smll.202504757. Epub 2025 Jul 22.
The stability and performance of perovskite quantum dot (PQD) solar cells are often compromised due to surface defects, phase transitions under ambient conditions, and inefficient charge transport caused by random packing and long-chain insulating ligands. This study introduces a conjugated polymer ligand strategy to simultaneously address these challenges by enhancing both charge transport and nanocrystal packing orientation. Unlike conventional insulating ligands, these conjugated polymers exhibit strong interaction with PQD surfaces while facilitating preferred PQD packing through π-π stacking interactions, a mechanism previously unexplored in PQD assemblies. Functionalized with ethylene glycol side chains, these polymers effectively reduce defect density, improve crystallinity, and enhance inter-dot coupling, leading to superior charge transport pathways. As a result, devices incorporating these polymers achieve a significantly improved maximum power conversion efficiency of over 15%, compared to 12.7% for pristine devices, with notable enhancements in short-circuit current density and fill factor. Furthermore, these devices demonstrate exceptional stability, retaining over 85% of their initial efficiency after 850 h. These findings establish conjugated polymer ligands as a dual-functional strategy for passivation and controlled PQD assembly, unlocking new pathways for high-performance and stable PQD solar cells suitable for real-world optoelectronic applications.
由于表面缺陷、环境条件下的相变以及随机堆积和长链绝缘配体导致的电荷传输效率低下，钙钛矿量子点（PQD）太阳能电池的稳定性和性能常常受到损害。本研究引入了一种共轭聚合物配体策略，通过增强电荷传输和纳米晶体堆积取向来同时应对这些挑战。与传统的绝缘配体不同，这些共轭聚合物与PQD表面表现出强烈的相互作用，同时通过π-π堆积相互作用促进PQD的择优堆积，这是一种此前在PQD组装体中未被探索的机制。这些聚合物通过乙二醇侧链功能化，有效降低了缺陷密度，提高了结晶度，并增强了点间耦合，从而形成了优异的电荷传输路径。结果，与原始器件的12.7%相比，包含这些聚合物的器件实现了显著提高的超过15%的最大功率转换效率，短路电流密度和填充因子也有显著提高。此外，这些器件表现出卓越的稳定性，在850小时后仍保持其初始效率的85%以上。这些发现确立了共轭聚合物配体作为一种用于钝化和可控PQD组装的双功能策略，为适用于实际光电应用的高性能和稳定的PQD太阳能电池开辟了新途径。
