P – N FR for fire safety and PV performance

Novel PIN FR in TPU combined fire performance with photoluminescence, transparency, mechanical performance: nitrilotris(ethane-2,1-diyl) tris (diphenylphosphinate) (NEDP). At 9% loading in TPU (thermoplastic polyurethane elastomers), UL 94 V-0 was achieved. Applied as 0.01 mm film, the TPU-NEDP compound shows photoluminescence (emitting visible blue light under UV) and 80% light transmission. This resulted in a +0.8% increase in photovoltaic conversion efficiency when the film was applied to flexible PV cells.

“Recyclable flame retardant, luminescent, and transparent thermoplastic polyurethanes: applications in light conversion films for flexible solar cells”, L-W. Su et al., Chemical Engineering Journal 517 (2025) 164436, https://doi.org/10.1016/j.cej.2025.164436