Quantum　dot　(QD)　based　light-emitting　diode　devices　(QLEDs)　attracted　significant　academic　interest　due　to　their　outstanding　color　saturation　and　convenient　solution-based　manufacturing　processes.　Currently,　the　external　quantum　efficiency　(EQE)　of　red,　green,　and　blue　QLEDs　reached　their　own　theoretical　limits.　However,　there　was　still　a　common　phenomenon　of　roll-off　existed　in　QLEDs.　In　this　work,　QLEDs　with　an　ultra　low　roll-off　were　realized　via　simple　carrier　injection　regulation　strategy　in　achieving　carrier　recombination　balance　and　exhibited　excellent　repeatability.　By　modifying　quantum　dots　and　electron　transport　layer　(ETL),　the　champion　device　with　the　peak　EQE　of　15.2　%,　and　a　current　efficiency　(CE)　of　63.4　cd/A　was　successfully　fabricated,　which　were　1.9　and　2.0　times　greater　than　those　of　the　control　devices,　respectively.　The　devices　delivered　a　peak　brightness　of　266,778　cd/m2,　and　the　EQE　remained　at　15.0　%　at　a　brightness　of　50,000　cd/m2,　staying　above　14　%　within　the　range　of　3000　to　200,000　cd/m2.　At　a　voltage　of　10　V,　the　peak　EQE　of　the　optimized　devices　decreased　by　only　7.6　%　when　compared　with　their　optimum　value　of　EQEs,　while　the　EQE　of　the　control　device　declined　by　26.6　%.　Finally,　analysis　of　40　different　batches　of　devices　revealed　an　average　EQE　of　14.3　%,　demonstrating　that　this　strategy　exhibited　good　repeatability.　This　approach　provided　a　convenient　means　to　regulate　carrier　injection　and　further　elucidated　the　relationship　between　roll-off　and　carrier　injection　balance　in　QLEDs,　proposing　a　strategy　to　enhance　their　performance　and　simultaneously　mitigate　roll-off.　©　2025　Elsevier　B.V.