Transparent Photovoltaic Technologies: Materials, Device Physics, Trade-Offs, and Future Directions.

Transparent photovoltaics (TPVs) are a transformative solar technology that can simultaneously generate electricity and transmit visible light, making them well-suited for integration into windows, building facades, vehicles, and wearable electronics. Unlike conventional opaque solar cells, which require surface areas for installation, TPVs expand the usable area for solar energy conversion without compromising architectural and visual harmony. This review examines recent advances in TPVs technologies, with a particular focus on material systems, device physics, device architecture, and emerging applications. TPVs materials include perovskites, organic semiconductors, quantum-dots, and thin-film silicon. The advanced transparent conductive electrodes are systematically discussed in terms of optical selectivity, charge transport, and operational stability. This review also addresses the trade-off between achieving optical transparency while maintaining competitive power conversion efficiency, identifying key scientific barriers that currently limit commercial implementation. The particular attention is given to challenges surrounding large-scale manufacturing, environmental degradation, color neutrality, and the lack of standardized testing and evaluation protocols. The application of TPVs includes smart windows, agrivoltaics, automotive systems, and self-powered electronics. The review concludes by outlining future directions such as tandem cell designs, photonic engineering, and sustainable TPVs system, while highlighting the questions that remain unresolved.