Sol-gel processed vanadium oxide as efficient hole injection layer in visible and ultraviolet organic light-emitting diodes

Room-Temperature Photodeposited Amorphous VOx Hole-Transport Layers for Organic Devices

“…Solution-processed VO x HILs in OLEDs have also been reported to be advantageous. − In addition to OPV devices, OLED devices made with VO x as the HIL were fabricated and contrasted with devices made with PEDOT:PSS, using an architecture of ITO/HTL/super yellow /PFN/Ag; these were fabricated in a manner similar to OPV devices. Estimated layer thicknesses are PEDOT:PSS: 30 nm, VO x : 5 nm, super yellow: 80 nm, PFN: 10 nm, and Ag: 100 nm.…”

Advances in Solution‐Processed OLEDs and their Prospects for Use in Displays

“…The energy bar rier to charge injection exists at the interface between the elec trodes and the chargetransporting organic semiconductors, so the energylevel alignment between the WF of the electrodes and the HOMO or the LUMO energy levels of the semiconduc tors should be carefully considered when selecting MOs. [105] HighWF MOs such as MoO 3 (6.82 ± 0.05 eV), [108] V 2 O 5 (6.8 ± 0.1 eV), [23,109] and WO 3 (6.8 ± 0.4 eV) [110] have a deep VB similar to the HOMO energy level of organic HTL, so they can facilitate efficient hole injection by reducing the hole injection energy barrier. [110] Solutionprocessed MoO 3 and WO 3 HILs have been used instead of conventional poly(3,4ethylene dioxythiophene):poly (styrene sulfonate) (PEDOT:PSS) HIL material.…”

Achieving highly efficient bipolar near-ultraviolet emitters via regulating the energy levels of the excited states by a co-acceptor system

“…[3][4][5]11 To overcome these problems, researchers have reported a variety of molecular configurations to obtain highly efficient NUV emitters. For example, (i) pure hydrocarbon aromatics featuring highly delocalized conjugated systems, which would be beneficial for charge transportation and recombination in OLEDs, while their high rigidity could enhance the thermal and morphological stabilities, which would be beneficial to improving the device duration; [12][13][14][15] (ii) introducing a heterocyclic aromatic ring with electron-donating heteroatoms into the NUV emitters to construct p-type emitters with good hole-transporting abilities; [16][17][18] (iii) construction of n-type NUV emitters by introducing electronaccepting groups, such as sulfonyl and triphenylphosphine oxide, 6,[19][20][21][22] (iv) by combining the advantages of unipolar p-type and n-type emitters in bipolar emitters for both hole and electron injection/transportation. [23][24][25][26] Compared with unipolar p-type or n-type emitters, bipolar emitters can participate in the injection/transportation of both electrons and holes, which is beneficial to charge-carrier recombination and exciton confinement in the luminescent layer.…”