The　structural,　electronic,　and　optical　properties　of　pristine　Ba2ZnS3　and　Mn4+　doped　Ba2ZnS3　at　Ba-site　have　been　carried　out　by　employing　the　first-principles　calculations　based　on　density　functional　theory　(DFT).　For　the　calculation　of　exchange　and　correlation　interactions,　the　modified　Becke　Johnson　(TB-mBJ)　potential　and　generalized　gradient　approximation　with　the　Hubbard　parameter　(GGA　+　U)　were　used　for　pristine　and　Mn4+　doped　Ba2ZnS3　respectively.　The　defective　states　due　to　Mn4+　doping　are　introduced　below　the　conduction　band　which　produces　n-type　conductivity　in　both　spin-up　and　spin-down　states.　The　direct　band　gaps　are　observed　for　Ba2ZnS3　and　Ba2ZnS3:Mn4+　(spin　up　and　spin　down)　with　bandgap　values　3.157　eV,　1.582　eV,　and　2.176　eV　respectively.　For　spin-up　states,　the　intermediate　states　are　induced　due　to　the　majority　contribution　of　s-orbital　of　Mn　atom,　while　minority　contribution　of　p-orbital　of　Mn　atom.　For　spin-down　states,　the　defective　states　are　produced　as　a　result　of　the　prominent　contribution　of　d-orbital　of　Mn　atom　and　minor　contribution　of　s-orbital　of　Mn　atom.　The　optical　properties　such　as　the　real　and　imaginary　parts　of　the　dielectric　function,　reflectivity,　electron　energy　loss　spectrum,　extinction　coefficient,　refractive　index,　absorption　coefficient,　and　optical　conductivity　as　a　function　of　photon　energy　are　calculated.　Our　results　revealed　that　Mn4+　doped　Barium　zinc　sulfide　emerged　as　a　highly　efficient　luminescent　phosphor　material,　and　is　more　suitable　for　optical　devices　due　to　its　direct　bandgap　nature　and　small　bandgap　value　(1.582eV).　©　2021　Elsevier　Inc.