Photovoltaics beyond Silicon: Interfacial Engineering, Sustainable Processing, and Data-Driven Design for High-Efficiency and Durable Solar Energy Systems

Silicon-based photovoltaics have established unmatched technological maturity, yet their intrinsic rigidity, indirect bandgap–related optical losses, and high-temperature processing requirements continue to constrain further diversification into lightweight, flexible, and low-carbon energy systems. Addressing these limitations has driven the rapid emergence of alternative photovoltaic platforms with tunable electronic structures and solution-processable architectures. This review provides a critical insight of interfacial phenomena that dictate efficiency and operational stability across perovskite, organic, quantum-dot, two-dimensional, metal organic frame work/covalent organic framework-based, MXene, and ferroelectric solar cells. Central emphasis is placed on how energy-level alignment, defect passivation, ion-migration control, and charge-selective layer engineering collectively shape charge extraction, recombination dynamics, and long-term durability. In addition, recent advances in sustainable processing routes, particularly deep eutectic solvent systems and low-temperature deposition strategies, are evaluated for their potential to enable environmentally benign and scalable device fabrication. In parallel, data-driven methodologies, including machine learning for materials discovery, interface optimization, and performance prediction, are assessed as transformative tools for accelerating the development of emerging photovoltaic technologies. By integrating interfacial chemistry, green processing, and computational design, this review outlines cross-cutting design principles and a forward-looking roadmap toward high-efficiency, stable, and scalable photovoltaics beyond silicon.