All　inorganic　cesium　lead　halide　(CsPbX3,　X=Cl,　Br,　I)　perovskites,　as　a　best　candidate　in　perovskite　family,　have　attracted　great　interest　due　to　their　fascinating　optical,　chemical　and　semiconducting　properties　and　have　demonstrated　as　potential　building　blocks　in　various　applications　such　as　photodetectors,　light-emitting　diodes,　solar　cells　and　lasers.　Numerous　efforts　have　been　made　to　develop　various　CsPbBr3　perovskites　with　tunable　morphology　such　as　quantum　dots　(0-D),　nanowires　(1-D)　and　nanoplates　(2-D)　to　achieve　desired　properties.　Among　them,　anisotropic　colloidal　quasitwo-　dimensional　nanoplates　have　been　attracting　a　great　deal　of　research　enthusiasm.　In　this　work,　all-inorganic　CsPbBr3　perovskite　nanoplates　were　prepared　by　precisely　controlling　the　synthesis　temperature　and　time　in　the　hot-injection　method.　The　reaction　was　performed　under　the　protective　atmosphere　of　nitrogen,　at　110°C　for　5　s　and　the　reaction　mixture　was　cooled　by　ice-water　bath.　Afterwards,　the　solution　was　purified　by　centrifugation　at　12000　r　min1　and　the　precipitates　were　dissolved　in　n-octane.　The　structure,　morphology　and　optical　properties　of　as-synthesized　CsPbBr3　perovskite　nanoplates　were　characterized　and　analyzed　by　the　series　of　characterization　techniques.　The　results　show　that　a　sharp　PL　emission　was　detected　at　the　peak　of　500　nm　with　a　narrow　full　width　at　the　half　maximum　(FWHM)　of　26　nm.　The　high-resolution　transmission　electron　microscopy　(HR-TEM)　showed　that　the　as-prepared　CsPbBr3　nanoplates　were　uniform　in　size,　with　an　average　length　of　20-21　nm　and　a　thickness　of　3-5　nm.　All　the　above　studies　evidenced　that,　the　improved　high　temperature-injection　method　have　yielded　the　CsPbBr3　perovskite　nanoplates　with　uniform　size　distribution,　high　color　purity　and　improved　optical　properties.　In　addition,　light　emitting　diode　(LED)　with　CsPbBr3　perovskite　nanoplates　as　the　perovskite　luminescent　layer　were　fabricated　by　the　simple　solution　spin-coating　and　vacuum　evaporation　technique.　The　device　structure　of　the　LED　is　ITO/PEDOT:PSS/TFB/CsPbBr3　NPs/TPBI/LiF/Al.　In　the　device　configuration,　the　patterned　ITO　is　used　as　the　anode,　the　spin-coated　TFB　with　larger　hole　mobility　is　used　as　the　hole　transport　layer,　vacuum　evaporated　TPBI　is　chosen　as　the　electron　transport　layer,　as-prepared　CsPbBr3　perovskite　nanoplates　are　used　as　the　light　emitting　active　layer,　and　the　vacuum　evaporated　LiF　as　the　electron　injection　layer　with　Al　cathode.　The　external　quantum　efficiency　(EQE)　of　1.71%　and　the　luminous　brightness　of　297　cd　m2　was　achieved　for　the　LED　devices　fabricated　by　the　solution　method.　Moreover,　the　densification　and　roughness　of　CsPbBr3　perovskite　nanoplates　as　the　luminescent　layers　were　measured　by　atomic　force　microscopy　(AFM).　The　improved　efficiency　and　performance　of　our　device　was　directly　related　to　the　compact　and　smooth　surface　of　CsPbBr3　luminescent　active　layer.　This　result　lays　a　foundation　for　the　fabrication　of　high　efficiency　light　emitting　diode　devices　by　utilizing　all-inorganic　CsPbBr3,　and　provides　a　relatively　simple　method　for　the　synthesis　of　CsPbBr3　nanoplates,　as　well　as　good　repeatability　of　thin　film　device　fabrication　process.　©　2019,　Science　Press.　All　right　reserved.