A　solution-processed　molybdenum　oxide　(MoOx)　as　the　hole　injection　layer　(HIL)　by　doctor-blade　coating　was　developed　to　improve　the　efficiency　and　lifetime　of　red-emitting　quantum-dot　light-emitting　diodes　(QD-LEDs).　It　has　been　demonstrated　that　by　adding　isopropyl　alcohol　into　the　MoOx　precursor　during　the　doctor-blade　coating　process,　the　morphology,　composition,　and　the　surface　electronic　structure　of　the　MoOx　HIL　could　be　tailored.　A　high-quality　MoOx　film　with　optimized　charge　injection　was　obtained,　based　on　which　all-solution-processed　highly　efficient　red-emitting　QD-LEDs　were　realized　by　using　a　low-cost　doctor-blade　coating　technique　under　ambient　conditions.　The　red　QD-LEDs　exhibited　the　maximum　current　efficiency　and　external　quantum　efficiency　of　16　cd/A　and　15.1%,　respectively.　Moreover,　the　lifetime　of　red　devices　initializing　at　100　cd/m(2)　was　3236　h　under　ambient　conditions,　which　is　about　twice　as　long　as　those　with　a　conventional　poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate)　HIL.　Large-area　QD-LEDs　with　4　in.　emitting　areas　were　fabricated　with　blade　coating　as　well,　which　exhibit　a　high　efficiency　of　12.1　cd/A　for　red　emissions.　Our　work　paves　a　new　way　to　the　realization　of　efficient　large-area　QD-LEDs,　and　the　processing　and　findings　from　this　work　can　be　expanded　into　next-generation　lighting　and　flat-panel　displays.