Recently,　hexagonal　boron　nitride　(h-BN),　an　ultra-wide　bandgap　semiconductor,　has　attracted　considerable　attention　owing　to　its　excellent　properties.　In　thin　films　grown　on　metal　catalysts,　contamination　and　damage　induced　by　a　transfer　process　cannot　be　avoided.　Therefore,　synthesizing　h-BN　films　on　non-catalytic　dielectric　substrates　is　desirable　for　electronic　applications.　In　this　study,　we　demonstrate　the　direct　growth　of　high-quality　h-BN　films　with　a　controllable　thickness　on　sapphire　substrates　by　using　the　pulsed　laser　deposition　(PLD)　technique.　The　effects　of　the　deposition　conditions　and　laser　parameters　on　the　growth　of　the　h-BN　films　are　systematically　investigated　by　evaluating　their　characteristic　Raman　peaks.　Among　the　various　growth　parameters　studied,　the　substrate　temperature　has　the　greatest　influence　on　the　crystalline　quality　of　the　h-BN　films,　and　the　optimal　pressure　varies　depending　on　the　target-substrate　distance.　The　h-BN　film　grown　under　optimal　conditions　exhibits　a　narrow　Raman　line　width　of　∼30　cm−1,　indicating　a　high　crystalline　quality.　The　photodetectors　fabricated　from　the　PLD-grown　h-BN　films　exhibit　superior　deep-ultraviolet　detection　performance　with　a　large　on/off　ratio　of　＞104,　high　photoresponsivity,　and　a　sharp　cut-off　wavelength　of　220　nm.　This　study　presents　the　possibility　of　producing　high-quality　h-BN　films　by　applying　PLD　on　dielectric　substrates　for　optoelectronic　applications.　©　2021