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

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 Ti3C2Tx film, in which its function is modulated by controlling the size of Ti3C2Tx nanosheets. Benefitting from a matched Fermi energy of Ti3C2Tx film, the Ti3C2Tx-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 Ti3C2Tx hole injection layer. In addition, the Ti3C2Tx 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.

Automated summary

The dual hole injection structure fabricated through the introduction of Ti3C2Tx film significantly enhances the external quantum efficiency of blue QLEDs. The modified Ti3C2Tx devices exhibit a 67% increase in peak EQE compared to the reference devices. This improvement can be attributed to the reduced energy barrier between ITO and PEDOT:PSS and the enhanced electrical stability of the ITO/PEDOT:PSS interface due to the Ti3C2Tx hole injection layer.