Pros and cons of hole-selective self-assembled monolayers in inverted PSCs and TSCs: extensive case studies and data analysis

Abstract

Inverted perovskite solar cells (PSCs) have garnered increased attention, achieving a notable power conversion efficiency (PCE) of 26.1%, surpassing that of the n–i–p configuration. This significant progress within the perovskite community owes much to the advancement and application of hole-selective self-assembled monolayers (HSSAMs). Representing a novel category of hole-selective layers (HSLs), HSSAMs offer several advantages. They are cost-effective, enable easy modulation of the substrate's work function, facilitate effortless interface modification, demonstrate minimal optical and electrical losses, and are compatible with conformal coatings and tandem solar cells (TSCs), thereby accelerating the advancement of inverted PSCs. This review systematically categorizes and evaluates the multifaceted roles of HSSAMs with diverse structures in inverted PSCs and TSCs, encompassing various anchoring and functional groups. Furthermore, an extensive analysis of literature data was conducted to summarize the deposition methods of hole-selective molecules with alternative structures and explore their relationship with device photovoltaic parameters and stability. Concurrently, an overview of the current status of HSSAMs is provided. This timely review offers a distinct perspective on the perovskite photovoltaic community and valuable insights into the ongoing development of these promising materials.