Efficient full-colour organic light-emitting diodes based on donor-acceptor electroluminescent materials with a reduced singlet-triplet splitting energy gap.

A series of efficient blue-emitting materials, namely, Cz-DPVI, Cz-DMPVI, Cz-DEPVI and TPA-DEPVI, possessing a donor-acceptor architecture with dual carrier transport properties and small singlet-triplet splitting is reported. These compounds exhibit excellent thermal properties with a very high glass-transition temperature ( ), and thus, a stable uniform thin film was formed during device fabrication. Among the weak donor compounds, specifically, Cz-DPVI, Cz-DMPVI and Cz-DEPVI, the Cz-DEPVI-based device showed the maximum efficiencies (: 13 955 cd m, : 4.

A hybrid inorganic-organic light-emitting diode using Ti-doped ZrO as an electron-injection layer.

We have fabricated stable efficient iridium(iii)-bis-5-(1-(naphthalene-1-yl)-1-phenanthro[9,10-]imidazole-2-yl) benzene-1,2,3-triol (acetylacetonate) [Ir(NPIBT) (acac)] doped inverted bottom-emissive green organic light-emitting diodes using Ti-doped ZrO nanomaterials as the electron injection layer. The current density () and luminance () of the fabricated devices with Ti-doped ZrO deposited between an indium tin oxide cathode and an Ir(NPIBT) (acac) emissive layer increased significantly at a low driving voltage (V) compared with control devices without Ti-doped ZrO. The Ti-doped ZrO layer can facilitate the electron injection effectively and enhances the current efficiency ( ) of 2.