Enhanced Photon Extraction Using Micro-Structured Luminescent Downshifting Layers for Smart Greenhouses

Optimising spectral conversion and directional control of sunlight is essential for advancing agrivoltaic greenhouse design. We present a comparative Monte Carlo ray-tracing study of large-area, thick luminescent downshifting (LDS) roofing sheets, focusing on inward-facing bottom microstructures to maximise downward photon delivery to crops. LDS sheets, comprising high-efficiency phosphors embedded in a PMMA matrix, were benchmarked against luminescent solar concentrators (LSCs) of identical dimensions. Simulations reveal that thick LDS layers achieve higher downward extraction (DE) efficiency than LSCs, with performance gains amplified through upscaling. Geometry-specific analyses show that, at equal surface feature density, micro-cuboids deliver the highest DE efficiency (57%), outperforming domes, pyramids, and cones due to their larger facet area and reduced angular selectivity. While all micro-structures enhance DE, optimised cuboidal designs offer a distinct advantage. Results further confirm that DE increases with device area, reinforcing the scalability of thick LDS architectures for commercial greenhouse integration. This work demonstrates the potential of micro-structured LDS roofing to improve crop illumination, spectral management, and overall greenhouse productivity.

Subject Matter Level: Introductory - Assumes little previous knowledge of the topic

What You Will Learn:
• Spectral energy conversion materials and technologies for agriculture applications

Who Should Attend:
• Anybody interested in materials for greenhouses
• Students and researchers with an interest in the spectroscopy of spectral conversion materials

About the Presenter: Juvet Fru from Karlsruhe Institut fur Technologie

Dr. Juvet Nche Fru received his Ph.D. in Physics from the University of Pretoria, South Africa, in 2021. He also earned an M.Sc. in Materials Science and Engineering from the African University of Science and Technology, Abuja, Nigeria (2016), and an M.Sc. in Physics from the University of Buea, Cameroon (2011).