Developing　lead-free　hybrid　metal　halides　with　stable　and　efficient　white-light　emission　remains　a　critical　challenge　for　next-generation　optoelectronics.　Here,　we　report　a　polar　zinc-based　organic-inorganic　hybrid　halide,　[EMPA]2Zn3Br12　(EMPA　=　5-[(4-ethylpiperazin-1-yl)methyl]pyridin-2-amine),　which　exhibits　broadband　white-light　emission　with　a　high　color　rendering　index　of　90　and　high　photoluminescence　quantum　yield　of　43.9%.　The　material　shows　nonlinear　optical　properties　with　a　measurable　second-harmonic　generation　response.　Unlike　conventional　hybrid　halides,　[EMPA]2Zn3Br12　demonstrates　exceptional　stability,　retaining　its　structure　and　luminescent　properties　after　60　days　of　immersion　in　water　and　prolonged　exposure　to　UV　irradiation.　Temperature-dependent　photoluminescence　measurements　reveal　that　the　material　maintains　its　white-light　emission　from　room　temperature　down　to　260　K.　Density　functional　theory　calculations　suggest　that　the　broadband　emission　originates　from　multiple　self-trapped　exciton　states,　facilitated　by　Jahn-Teller　distortions　in　the　[ZnBr4]2-　tetrahedra.　Furthermore,　a　white-light-emitting　diode　fabricated　using　[EMPA]2Zn3Br12　as　a　single　component　white　light　emitter,　demonstrating　its　potential　for　solid-state　lighting.　This　study　highlights　[EMPA]2Zn3Br12　as　a　promising　lead-free　alternative　for　environmentally　friendly　high-performance　white-light-emitting　and　optoelectronic　applications.