All-inorganic　zero-dimensional(0D)metal　halides,　owing　to　their　intriguing　optical　properties　and　easy　solution　processibility,　are　emerging　as　a　new　generation　of　luminescent　materials　and　as　an　alternative　to　lead　halide　perovskites　for　various　applications　such　as　solid-state　lighting　and　photodetectors.　Herein,　a　new　yellow　phosphor　is　developed　based　on　Cd2+-doped　Cs2ZnCl4,　which　exhibits　intense　broadband　and　long-lived(11.　4　ms)photoluminescence(PL)at　565　nm　upon　270　nm　excitation,　with　a　PL　quantum　yield　up　to　46.　0%.　Temperature-dependent　PL　spectroscopic　analyses　reveal　that　the　broadband　PL　originates　from　the　forbidden　3E→1A1　transition　of　Cd2+.　Specifically,　localized　exciton　emission　is　observed　at　low　temperatures　below　170　K,　in　parallel　with　efficient　energy　transfer　from　the　localized　excitons　to　Cd2+.　Besides,　the　phosphor　displays　an　excellent　anti-thermal　quenching　property,　remaining　90%　PL　intensity　at　150　℃　in　comparison　with　that　at　room　temperature.　These　findings　provide　not　only　new　insights　into　the　excited-state　dynamics　of　Cd2+　in　metal　halides,　but　also　a　new　avenue　for　the　exploration　of　novel　and　efficient　luminescent　materials　based　on　0D　metal　halides.　©　2023　Chines　Academy　of　Sciences.　All　rights　reserved.