Multi-color display and its model for a white OLED combined with optical color filters

Development of efficient and durable sources of white light

“…A broad spectrum OLED has been demonstrated having a single emission layer comprising a green‐emitting host material, a tris(pyrenylbenzene), with red and blue dopants, which yields a device of high brightness and stability but inferior efficiency [62]. Similarly a green–white‐emitting host material [the zinc complex of a bis(hydroxyphenylbenzthiazole) doped with a red–yellow (λ = 550 nm) fluorescent dye (rubrene)] yielded a bright white light source [63]. Rubrene is a tetraphenylnaphthacene which is used in the novelty chemiluminescent lightsticks sold at many outdoor events [64,65].…”

Efficient white polymer light-emitting diodes (WPLEDs) based on covalent-grafting of [Zn2(MP)3(OAc)] into PVK

“…In this regard, benefiting from the volatility of most Zn( ii )-complexes, a vacuum-deposition procedure for their WOLEDs was employed. One approach is through the mixing of Zn( ii )-complex-based primary colours in a single emitting layer, where the high-energy-state Zn( ii )-complex as the host 16 and/or sensitizer 17 and the low-energy-state complex as the guest 18 can be adopted to produce electrically-driven white light with the desired energy transfer between multiple small-molecule chromophores. Another alternative relies on a multilayer structure consisting of two or more separate emitting layers for WOLEDs, where the superposition of a Zn( ii )-complex within different primary colours, 19 and/or an additional colour-compensation layer by exciplex formation, 20 is also capable of white-light modulation.…”

“…In comparison, multi-layered WOLEDs, 19,20 especially those with facilitated carrier-transport abilities, exhibit significantly higher efficiencies ( η c = 1.39–1.65 cd A −1 to 5.2 cd A −1 and η p up to 1.43 lm W −1 ) at high luminance (10 3 –10 4 cd m −2 ) than those ( η c = 0.12–0.28 cd A −1 and η p = 0.018–0.082 lm W −1 at 10 2 –10 3 cd m −2 ) of single-unit devices. 16–18 Nonetheless, besides the inevitable high cost of the vacuum-deposition procedure, unsatisfactory device performance-based crystallization and discrepant components-induced white-light instability pose problems for the two strategies. Convincingly, the circumvention of these problems, to some extent, cannot depend on Zn( ii )-based white-light-emitting coordination polymers 21 with a lack of inherent processing ability, but can only rely on the doping of Zn( ii )-complexes 22 and/or sensitizers 23 into a polymeric host with a deep LUMO–HOMO bandgap for solution-processable and large-area WPLEDs.…”

Bis[2-(4′-Bromopyrazolyl-1′)-3-Tosylaminopyridinato]zinc(II): Synthesis, structure, and luminescence properties

“…The OLED devices were produced in which the heterocyclic zinc(II) complexes with 2 (2' hydro xyphenyl)benzimidazole [9][10][11], 2 (2' hydroxyphe nyl)benzoxazole [12][13][14], 2 (2' hydroxyphenyl)ben zothiazole [15][16][17][18][19][20], and 2 (2' tosylaminophenyl)ben zoxazole [21,22] were used as electroluminescent lay ers. These complexes are resistant to the exposure, light, and temperature.…”

“…Practical importance of these metal chelates is the use of such compounds as emitting layers in organic light emitting diodes (OLED) and also as electron transport layers in these devices. Metal chelates lumi nescing in the blue spectral range, for example, the zinc complexes with 7 azaindoles [1-3], di 2 pyridy lamine, 2,6 bis(2 pyridylamino)pyridine [4], 2,6 bis(benzimidazolyl)pyridine [5, 6], 1,3,4 oxadiazole, 2 (2' hydroxyphenyl) 5 phenyl 1,3 oxadiazole [7], and 2 (2' hydroxyphenyl) 2 oxazoline [8], which is rarely met for standard inorganic luminophores.The OLED devices were produced in which the heterocyclic zinc(II) complexes with 2 (2' hydro xyphenyl)benzimidazole [9-11], 2 (2' hydroxyphe nyl)benzoxazole [12][13][14], 2 (2' hydroxyphenyl)ben zothiazole [15][16][17][18][19][20], and 2 (2' tosylaminophenyl)ben zoxazole [21,22] were used as electroluminescent lay ers. These complexes are resistant to the exposure, light, and temperature.…”