Enhanced Hole Injection in Blue Quantum‐Dot Light‐emitting Diodes Utilizing Dual Hole Injection Layer of PEDOT:PSS/Ti3C2Tx

Abstract The low hole injection efficiency severely constrains the operational capability of blue quantum‐dot light‐emitting diodes (QLEDs). Constructing the structure of stepped energy levels is an effective approach to enhance the hole injection efficiency. Here, the dual hole injection structure is fabricated through the introduction of Ti 3 C 2 T x film, in which its function is modulated by controlling the size of Ti 3 C 2 T x nanosheets. Benefitting from a matched Fermi energy of Ti 3 C 2 T x film, the Ti 3 C 2 T x ‐modified devices achieve a peak external quantum efficiency (EQE) of 15.89%, exhibiting a 67% increase compared to the reference devices with an EQE of 9.72%. The enhanced EQE can be attributed to the reduced energy barrier between indium tin oxide (ITO) and PEDOT:PSS, resulting from the incorporation of a Ti 3 C 2 T x hole injection layer. In addition, the Ti 3 C 2 T x layer effectively avoids the corrosion of the ITO electrode by acidic PEDOT:PSS, thereby enhancing the electrical stability of the ITO/PEDOT:PSS interface. The results provide a new approach to realize the high‐performance blue QLEDs devices.