Carrier injection efficiencies and energy level alignments of multilayer graphene anodes for organic light-emitting diodes with different hole injection layers

Technical issues in graphene anode organic light emitting diodes

“…Because UPS measurements cannot locate the energy level of unoccupied energy levels, the LUMO level of Hat-CN cannot be positioned exactly. However, because the clear enhancement in J has been observed by using a Hat-CN HIL, the LUMO level of Hat-CN and HOMO level of TAPC must be very close, which implies the possibility of Fermi pinning of Hat-CN LUMO level [24]. In this work, we have introduced Hat-CN to modify the MLG/HTL interface.…”

“…Hat-CN is a high mobility strong n-type organic semiconductor, which can extract electrons from adjacent organics [10,22]. Thus the role of Hat-CN is not an energy barrier modifier but a charge generation layer (CGL) [23,24]. Under applied voltage, the electrons in the HOMO level of TAPC are extracted toward the Hat-CN LUMO level, which effectively contributes in hole generation in the TAPC layer.…”

Conductive Inorganic–Organic Hybrid Distributed Bragg Reflectors

“…Generally, a charge recombination and/or generation interface will be formed when the highest occupied molecular orbital (HOMO) of one organic semiconducting material and the lowest unoccupied molecular orbital (LUMO) of another organic semiconducting material are close to each other (for instance, m‐MTDATA and HAT‐CN), which will facilitate the charge transport in the composite films . To improve the conductivity of the hybrid DBRs, we came up with the strategy of utilizing the multi‐alternating organic semiconducting films instead of the single component film as the low‐refractive‐index units.…”

Microscale‐Patterned Graphene Electrodes for Organic Light‐Emitting Devices by a Simple Patterning Strategy

“…However, the shortages of intrinsic sensitivity to acid and heat, the low storage of indium on earth, and intrinsic mechanical brittleness have impeded its application in OLEDs, especially flexible OLEDs. For the purpose to replace ITO electrodes, other transparent conductive materials such as metallic films, metal nanowires, conducting polymers, carbon nanotubes, and graphene have been widely investigated. Among them, 2D material of graphene is one of the most promising materials for a flexible transparent electrode because of its high transparency, excellent electrical conductivity, mechanical stability, and ultrahigh carrier mobility …”