Two-dimensional reduced graphene oxide as high-efficiency hole injection layer for quantum dot light-emitting diodes

Area of Science:

• Materials Science
• Optoelectronics
• Nanotechnology

Background:

• Carrier injection imbalance is a major limitation in quantum dot light-emitting diodes (QLEDs).
• Development of efficient hole injection layers (HILs) is crucial for improving QLED performance.
• Graphene oxide (GO) and reduced graphene oxide (rGO) are explored for their potential in electronic devices.

Purpose of the Study:

• To prepare a high-performance reduced graphene oxide (rGO) hole injection layer (HIL) for quantum dot light-emitting diodes (QLEDs).
• To investigate the impact of thermally treated rGO on the optoelectronic properties of QLEDs.
• To demonstrate the potential of rGO as an advanced HIL for QLED optimization.

Main Methods:

• Graphene oxide (GO) was thermally treated at 160 °C for 30 min to produce reduced graphene oxide (rGO).
• rGO was utilized as a hole injection layer (HIL) in QLED devices.
• Optoelectronic performance metrics including turn-on voltage, luminance, external quantum efficiency (EQE), and current efficiency (CE) were measured.

Main Results:

• The rGO HIL tuned the work function to 5.04 eV, reducing hole injection barriers.
• rGO-based QLEDs exhibited a low turn-on voltage of 2.0 V and high luminance (120,000 cd m⁻²).
• Peak EQE and current efficiency were significantly enhanced, reaching 13.31% and 14.93 cd A⁻¹, respectively, with further optimization.

Conclusions:

• Thermally reduced graphene oxide (rGO) is an effective high-performance HIL for QLEDs.
• Enhanced conductivity and favorable work function of rGO contribute to improved device performance.
• rGO offers superior thermal stability and low-temperature operability, presenting a viable pathway for QLED advancement.