Quantum Dot‐Based Electron‐Transporting Materials for Perovskite Solar Cells

Perovskite solar cells (PSCs) emerge as one of the most promising photovoltaic technologies, achieving remarkable power conversion efficiencies (PCEs) in recent years. A critical factor in advancing PSC performance is the development of efficient and stable electron-transporting materials (ETMs). Quantum dots-based ETMs (QDs-ETMs) attract significant attention due to their unique electronic properties, tunable energy levels, potential for multiple exciton generation, and versatile surface chemistry enabled by functionalization with organic or inorganic ligands. Their ability to form dense and uniform distribution layers ensures effective charge separation, which is essential for achieving high-efficiency PSCs. In various architectures, QD-ETMs improve the bottom or top interface between the perovskite layer and the electron transport layer (ETL) and provide robust protection of the perovskite layer against moisture, oxygen, heat, and utlraviolet exposure. This review comprehensively examines recent progress in QD-ETMs for PSC applications, highlighting their advantages in enhancing charge transport, Fermi level alignment, and defect passivation. The tunability of quantum dots (QDs) through size and composition engineering offers precise control over the band structure, improving electron extraction while minimizing interfacial losses. Additionally, recent advances in surface passivation techniques enable QDs-ETMs to effectively reduce trap states and suppress non-radiative recombination, further enhancing device efficiency.