Versatile charge collection materials in perovskite photovoltaics

The burgeoning field of perovskite solar cells (PSCs) has achieved significant advancements, rivaling traditional photovoltaic technologies. However, efficient, and stable charge collection remains a critical hurdle for commercial deployment. This review aims to provide a comprehensive overview of various charge collection materials and their implications in perovskite photovoltaics. We assess state-of-the-art materials like indium tin oxide (ITO), conductive polymer, metal-based thin film, carbon-based alternatives, and more, exploring their optical properties, mechanical flexibility, electrical conductivity, and associated fabrication costs. While ITO remains the most commonly used due to its high transparency and conductivity, its scarcity and high-cost limit its scalability. Metal-based electrodes offer excellent conductivity and are emerging as leaders in applications requiring mechanical flexibility, but their permeation and interaction within perovskites need to be overcome. Carbon- and polymer-based materials offer stability and low cost but often suffer from lower conductivity. Each material class presents its own set of challenges, which must be addressed for real-world applications. This review also delves into innovative solutions, aiming to overcome these challenges, concluding by discussing the future potential and the key areas of research to realize durable, efficient, and cost-effective perovskite photovoltaics.