In　recent　years,　hybrid　metal　halides　have　gained　considerable　attention　for　optoelectronic　applications　due　to　their　outstanding　photophysical　properties,　despite　challenges　with　stability.　In　this　study,　we　present　the　design　and　synthesis　of　a　highly　stable　and　efficient　zero-dimensional　(0D)　hybrid　copper(i)　halide,　[FBZPA]4Cu5Br13　(FBZPA　=　protonated　1-(4-fluorobenzyl)piperazine)),　for　advanced　scintillation　and　solid-state　lighting　applications.　This　material　exhibits　efficient　yellow　light　emission　with　a　photoluminescence　quantum　yield　of　88.5%,　driven　by　radiative　recombination　of　self-trapped　excitons,　which　is　facilitated　by　structural　deformation　and　strong　electron-phonon　coupling　within　the　0D　structure.　[FBZPA]4Cu5Br13　shows　excellent　scintillation　properties,　including　a　high　light　yield　(∼39　100　photons　MeV−1),　a　low　detection　limit　(0.102　μGyair　s−1),　and　a　high　spatial　resolution　(15　lp　mm−1),　making　it　an　ideal　candidate　for　high　quality　X-ray　imaging.　Additionally,　we　fabricated　a　white　light-emitting　diode　(WLED)　by　combining　[FBZPA]4Cu5Br13　with　a　commercial　blue　phosphor　on　a　UV　chip.　The　WLED　exhibited　a　high　color　rendering　index　of　90　with　stable　emission.　It　demonstrates　remarkable　stability,　retaining　its　structure　and　optical　properties　after　exposure　to　water,　and　intense　light,　without　requiring　encapsulation　or　chemical　modifications.　This　study　highlights　[FBZPA]4Cu5Br13　as　a　promising　material　for　next-generation　scintillation　and　solid-state　lighting　applications.　©　2025　The　Royal　Society　of　Chemistry.