Based　on　the　gate　controlled　characteristics　of　GaN　High　Electron　Mobility　Transistors(HEMTs)　and　on　the　photovoltaic　effect　in　lead　zirconate-titanate(PZT)　ferroelectric　thin　films,　a　new　type　of　photosensitive　layer/HEMT　detector　structure　is　proposed.　For　this　purpose,　a　PZT　ferroelectric　thin　film　is　deposited　on　the　gate　of　a　HEMT　device　to　prepare　films　with　optimized　photovoltaic　performance,　the　surface　morphology　and　ferroelectric　properties　of　PZT　films　prepared　by　different　sputtering　powers　and　annealing　temperatures　are　analyzed.　It　is　found　that　the　best　conditions　for　the　grain　growth　on　the　surface　of　the　film　are　at　200　W　sputtering　power　and　700　annealing　temperature,　and　the　residual　polarization　intensity　is　38.0　μC•cm-2.The　output　characteristics　of　the　fabricated　photosensitive　gate　PZT/GaN-based　HEMT　devices　are　compared　to　those　of　pristine　HEMTs　under　both　dark　condition　and　365　nm　ultraviolet　light.　The　results　show　that　the　source　drain　saturation　voltage　of　the　HEMT　with　the　ferroelectric　thin　film　decreases　by　3.55　V　and　the　saturation　current　increases　by　5.84　mA,　compared　with　those　without　light,　clearly　indicating　a　significant　UV　photodetection　capability.　To　achieve　the　purpose　of　optimizing　the　structure　of　the　new　type　of　detector,　detectors　with　different　grid　lengths　such　as　1　μm,　2　μm,　and　3　μm　are　tested.　The　results　show　that　under　ultraviolet　light,　the　drain　saturation　currents　of　the　three　detectors　are　23　mA,　20　mA,　and　17　mA,　respectively.　Therefore,　the　longer　the　gate　length,　the　smaller　the　saturation　current　of　the　device,　and　the　worse　the　detection　performance.　©　2020,　Science　Press.　All　right　reserved.