Exploring lanthanide doped materials and their high-pressure optical properties is important from the perspective of designing pressure sensors,piezoelectric materials,scintillators,and optoelectronic devices,just to mention a few.Understanding the high-pressure optical properties of polymeric fibrous mats provides significant advantages in terms of flexibility,tunability,facile processability,and malleability.In this work,we have developed flexible polyvinylidene difluoride (PVDF) fibrous mats doped with an Eu3+ source of Eu(NO3)3·5H2O (EN-PF) or Eu2(SO4)3 (ES-PF) by a Forcespinning(R) method.Microstructural analysis of these two systems indicates that Eu(NO3)3·5H2O and Eu2(SO4)3 are homogeneously distributed and dispersed into the PVDF matrix.Fiber formation promotes a β-phase PVDF.Eu3+ doping increases the β-phase.Its fraction is larger for the ES-PF mats.To understand their high-pressure optical properties,their photoluminescence spectra have been taken at various pressures up to 58 GPa in a diamond anvil cell.High-pressure luminescence illustrates a clear change in asymmetry ratio,peak intensity,peak breadth,color coordinate,and color temperature of Eu3+ ions from both EN-PF and ES-PF with a different extent of changes.Specifically,Eu3+ ions in the ES-PF mats switch from asymmetric to symmetric environment as pressure increases.Those in the EN-PF mats present symmetric environment for all tested pressures.Both of the Eu3+ doped PVDF systems present irreversible changes.Therefore,the EN-PF fibrous mats present an opportunity to make pressure induced red-orange-yellow tunable phosphors for multifunctional applications.