MXenes for multifunctional optoelectronics: Advances, challenges, and roadmap

MXenes have emerged as transformative materials for optoelectronic applications, yet interfacial complexities and stability challenges restrict their full potential. While numerous studies have explored MXenes in individual devices, a unified perspective linking their material chemistry to multifunctional optoelectronic systems remains limited. This review provides a critical framework that connects MXene composition, surface terminations, and defect chemistry to device-level performance across four complementary pillars of optoelectronics: photovoltaics, photodetectors, neuromorphic devices, and light-emitting diodes. Together, these platforms represent the full functional cycle of light harvesting, sensing, information processing, and emission. We analyze how material synthesis routes and surface engineering govern interfacial energetics, charge transport, and switching dynamics, enabling MXenes to act as electrodes, charge-transport layers, and active components. By establishing the structure–property–device framework, we identify key chemical and environmental bottlenecks that hinder industrial scalability and propose a strategic roadmap toward durable, high-throughput MXene-based optoelectronic systems.