The　trap　characteristics　of　low-temperature　polysilicon　thin　film　transistors　(TFTs)　are　studied　using　a　current　transient　method　that　is　based　on　the　trapping　and　detrapping　of　charge　carriers　from　the　trap　sites　in　the　device.　Analysis　of　the　measured　current　transient　curve　allowed　three　types　of　detrapping　behavior　to　be　identified,　each　of　which　displayed　a　different　time　constant,　activation　energy,　and　spatial　position.　This　current　transient　method　can　be　integrated　into　the　negative　bias　temperature　instability　stress　test　used　for　the　reliability　study.　The　peak　amplitudes　of　the　traps　increase　because　of　the　stress　applied　in　the　test,　thus　demonstrating　that　the　degradation　mechanism　of　the　TFTs　is　closely　related　to　changes　in　the　traps　in　these　devices.　©　2021　IOP　Publishing　Ltd.