File Name : figs0a.jpg Caption : average raman spectra of different samples and standard deviation. the average value (¯x) are presented by the red lines, while the standard deviation of each point (σ) are presented by the grey line ( ¯x+σ, ¯x-σ). File Name : figs1.tif Caption : raman spectrum of pbi₂ resulting of placing fapbi₃ under an excitation power higher than 1 mw (λ=633nm). File Name : figs2.tif Caption : pl signal of the fapbi₃ polymorphs at rt: α_i (824 nm), α_δ (765 nm) and α_rec(814 nm). File Name : figs3.tif Caption : raman spectrum and pl signal of α_δ^*-fapbi₃. this corresponds to the α_δ-phase that appears in yellow needle-like fapbi₃ crystals. these are directly synthesized via heating the 1m fapbi₃+gbl solution at 70°c overnight. File Name : figs4a.tif Caption : fig. 5 temperature dependence of pl signal position of the transitions of fapbi₃: (a)α_i→α_ht and (b) α_rec→α_ht. File Name : figs5.tif Caption : temperature dependent xrd measurements of α_i-fapbi₃ scs. File Name : figs6a.tif Caption : comparison of experimental xrd patterns of as-prepared fapbi₃ thin film annealed at 120°c with: a) annealed at 80°c and 100°c and with b) simulated cubic pm¯3m and im¯3 patterns via le bail fitting. File Name : figs8a.tiff Caption : graphical representation of the results obtained from pawley refinement of the xrd patterns obtained at rt: (a) lattice constants of cubic (pm¯3m) phase and (b) full-width-at-half-maximum (fwhm) values for the corresponding 002- and 022-diffraction maxima. coloured points correspond to thin films prepared at noticed temperatures. on the abscissa, three polymorphs of the samples are given: as-prepared (α_i, cubic - 100%), degraded (α_δ, cubic – 19-24%, the rest is δ-phase) and recovered (α_rec, cubic – 77-93%, the rest is pbi₂).