Tailoring interfacial energetics in perovskite/silicon tandem solar cells: the converging roles of self-assembled monolayers and dipolar interlayers

Abstract

Perovskite/silicon tandem solar cells have emerged as a groundbreaking advancement in photovoltaic technology, presenting a viable route to exceed the efficiency ceiling imposed on conventional single-junction silicon devices. At the heart of this innovation lies the perovskite top cell, whose interfacial properties critically govern tandem performance, influencing carrier extraction, recombination dynamics, and long-term stability. Yet, complex interfacial interactions with charge transport layers often introduce challenges such as defect-induced recombination, energy level misalignment, and environmental degradation. This review surveys recent advances in interface engineering for perovskite top cells, focusing on self-assembled monolayers (SAMs) and dipole-tailored interlayers in both single-junction and tandem configurations. We first establish foundational energy alignment concepts – vacuum level shifts, Fermi level pinning, interfacial dipoles, and band bending to frame the electronic landscape at interfaces. The review then explores strategies including molecular dipole tuning, surface passivation, and chemical bonding modulation. This work uniquely integrates molecular-scale design into device performance and critically compares SAMs and dipolar layers with conventional methods. Finally, we highlight key challenges in scalability, industrial compatibility, and operational durability. By aligning molecular design with practical implementation, this review offers guiding principles for advancing interface chemistry in efficient, stable, and commercially viable tandem solar cells.