This Thematic Series covers OLED materials design, synthesis, characterization and utilization in devices. Materials include small molecule fluorophores, polymers, dendrimers, organometallic complexes, thermally activated delayed fluorescence compounds, compounds exhibiting aggregation induced emission, and compounds exhibiting triplet-triplet annihilation.
Graphical Abstract
Figure 1: Radiative deactivation pathways existing in fluorescent, phosphorescent and TADF materials.
Figure 2: Boron-containing TADF emitters B1–B10.
Figure 3: Diphenylsulfone-based TADF emitters D1–D7.
Figure 4: Triazine-based TADF emitters T1–T3, T5–T7 and azasiline derivatives T3 and T4.
Figure 5: Triazine-based TADF emitters T8, T9, T11–T14 and carbazole derivative T10.
Figure 6: Triazine-based TADF emitters T15–T19.
Figure 7: Triazine- and pyrimidine-based TADF emitters T20–T26.
Figure 8: Pyrimidine-based TADF emitters T27–T30.
Figure 9: Triazine-based TADF polymers T31–T32.
Figure 10: Phenoxaphosphine oxide and phenoxathiin dioxide-based TADF emitters P1 and P2.
Figure 11: CN-Substituted pyridine and pyrimidine derivatives CN-P1–CN-P8.
Figure 12: CN-Substituted pyridine derivatives CN-P9 and CN-P10.
Figure 13: Phosphine oxide-based TADF blue emitters PO-1–PO-3.
Figure 14: Phosphine oxide-based TADF blue emitters PO-4–PO-9.
Figure 15: Benzonitrile-based emitters BN-1–BN-5.
Figure 16: Benzonitrile-based emitters BN-6–BN-11.
Figure 17: Benzoylpyridine-carbazole hybrid emitters BP-1–BP-6.
Figure 18: Benzoylpyridine-carbazole hybrid emitters BP-7–BP-10.
Figure 19: Triazole-based emitters Trz-1 and Trz-2.
Figure 20: Triarylamine-based emitters TPA-1–TPA-3.
Figure 21: Distribution of the CIE coordinates of ca. 90 blue TADF emitters listed in this review.
Graphical Abstract
Scheme 1: Synthesis of complexes 2 and 3.
Figure 1: ORTEP representation of 3. Thermal ellipsoids are drawn at the 50% probability level. Selected bond...
Figure 2: UV–vis absorption spectra of complexes 2 and 3 measured in dichloromethane at room temperature.
Figure 3: Emission spectra of complexes 2 and 3 measured at room temperature and 77 K, 2 wt % in a PMMA matri...
Figure 4: Cyclic voltammograms of complexes 2 and 3, analyte concentration 10−4 M. Measured in DMF (0.1 M TBA...
Figure 5: Thin films of Pt(MPIM)(acac) left, Pt(MPIM)(mes) (2) middle, and Pt(MPIM)(dur) (3) right, 2 wt % in...
Figure 6: Photoluminescence spectra of 2 and 3 compared to the emission profile of Pt(MPIM)(acac), 2 wt % in ...
Figure 7: Localization of spin density on the complexes Pt(MPIM)(acac) left, Pt(MPIM)(mes) (2) middle, and Pt...
Graphical Abstract
Scheme 1: Molecular structures of isomers 1 and 2.
Figure 1: (a) The optimized S0 geometries of 1 (left) and 2 (right) on B3LYP/6-31G* level in gas phase; (b) T...
Figure 2: UV–vis (solid point) and photoluminescence (hollow point) spectra of 1 and 2 in dilute solution.
Figure 3: The low temperature photoluminescence spectra of 1 (left) and 2 (right) in toluene at 77 K.
Figure 4: (a) Time-resolved transient photoluminescence decay spectra of the doped films (8 wt % in CBP) meas...
Figure 5: Energy level (eV) diagrams of OLED devices and the chemical structures of the materials utilized fo...
Figure 6: J–V–L (current density–voltage–luminance) (left) and EQE–current density characteristics of the dev...
Figure 7: EQE–current density characteristics of the devices based on 1 (top) and 2 (bottom). The solid lines...
Graphical Abstract
Scheme 1: Synthetic routes of CEPDO and CBPDO.
Figure 1: Structures and molecular orbitals of (a) CEPDO and (b) CBPDO.
Figure 2: UV–vis absorption and photoluminescence spectra in DCM solution (1 × 10−5 M and 1 × 10−6 M, respect...
Figure 3: Cyclic voltammograms for CEPDO and CBPDO in DCM solution.
Figure 4: DSC and TGA curves of CEPDO and CBPDO.
Graphical Abstract
Figure 1: Molecular structure of neutral platinum(II) complex 1 bearing four monodentate ligands; cy = cycloh...
Figure 2: Chemical structure of the dinuclear Pt complexes 2a–b and 3 [20].
Figure 3: Molecular structure of platinum(II) complexes bearing isoquinolinylpyrazolates; dip = 2,6-diisoprop...
Figure 4: Selected neutral platinum(II) complexes featuring dianionic biazolate and neutral bipyridines [27].
Figure 5: Selected neutral platinum(II) complexes from bipyrazolate and carbene-based chelates [34,35].
Figure 6: Cyclometalated thiazol-2-ylidene platinum(II) complexes with different acetylacetonate ligands [37].
Figure 7: Neutral platinum(II) complexes 13–15 bearing azolate ligands [13].
Figure 8: Chemical structure of neutral platinum(II) complexes 16–18 bearing azine-pyrazolato bidentate ligan...
Figure 9: Molecular structure of carbene-containing cyclometallated alkynylplatinum(II) complexes 19–21 [41].
Figure 10: Chemical structure of platinum(II) complexes 22a–d bearing asymmetric C^N^N tridentate ligands [53].
Figure 11: Chemical structure of platinum(II) complexes 23 bearing bis-cyclometalating 2,6-dipyridylbenzene ty...
Figure 12: Molecular structure of dendritic carbazole-containing alkynyl-platinum(II) complexes 24a–d [62].
Figure 13: Molecular structure of bipolar alkynyl-platinum(II) complexes 25 bearing carbazole and electron-acc...
Figure 14: Molecular structures of neutral platinum(II) complexes comprising donor-acceptor alkynyls (26) or e...
Figure 15: Chemical structure of the asymmetric Pt(II) derivatives 28 bearing triazole and tetrazole moieties ...
Figure 16: Molecular structure of the tetradentate platinum complexes 29–32 bearing N^C^C^N and C^C^C^N ligand...
Figure 17: Chemical structure of the tetradentate Pt complexes 33–38 based on N^C^C^N-type of ligands [80-84].
Figure 18: Chemical structure of the macrocyclic tetradentate platinum complexes reported by Wang and co-worke...
Figure 19: Molecular structure of complex 41–46 [88,89].
Figure 20: Molecular structure of asymmetric derivatives 47–49 based on triaryl-type of bridge [90].
Figure 21: Chemical structure of the asymmetric tetradentate derivatives 50 and 51 based on spirofluorene link...
Figure 22: Molecular structure of the pyridylazolate-based complexes 52–54 reported by Chi and co-workers [97].
Figure 23: Chemical structure of the red-to-NIR emitting complexes 55–57 bearing donor–acceptor triphenylamino...
Figure 24: Molecular structures of the Pt(IV) derivatives 58 and 59 employed as triplet emitters in solution-p...