A novel candle light-style OLED with a record low colour temperature

Korshunov, Vladislav M.; Chmovzh, Timofey N.; Knyazeva, Ekaterina A.; Taydakov, Ilya V.; Mikhalchenko, Ludmila V.; Varaksina, Evgenia A.; Saifutyarov, Rasim S.; Avetissov, Igor; Ракитин, Олег А.

doi:10.1039/c9cc04973h

Cited by 22 publications

(17 citation statements)

References 29 publications

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“…1,2,5-Chalcogenadiazoles and especially their fused derivatives (chalcogen E = S, Se, Te; Scheme ) are important for chemistry, materials science, and biomedicine. − Notably, they feature Lewis ambiphilicity, i.e., the ability to be Lewis acids and bases simultaneously, − which is dualistic since in both acidic and basic behavior both σ- and π-molecular orbitals (MO) are involved. Examples include the self-association of 1,2,5-chalcogenadiazoles by means of [E···N] 2 supramolecular synthons in crystal lattices of neutral ,− and charged derivatives covering 1,2,5-chalcogenadiazolidyl and 1-methyl 1,2,5-chalcogenadiazolylium salts; the formation of radical anions (RAs) ,,− and charge transfer (CT) complexes (where they can function as both A and D); ,− and metal coordination compounds ,− (Scheme ).…”

Section: Introductionmentioning

confidence: 99%

Lewis Ambiphilicity of 1,2,5-Chalcogenadiazoles for Crystal Engineering: Complexes with Crown Ethers

Chulanova

Radiush

Shundrina

et al. 2020

Crystal Growth & Design

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The cocrystallization of 1,2,5-chalcogenadiazoles (chalcogen E = S, Se, and Te) with cyclic polyethers 18-crown-6 (18-c-6) and dibenzo-18-crown-6 (db-18c-6) yielded the molecular complexes characterized by X-ray diffraction and thermogravimetry/differential scanning calorimetry techniques together with density functional theory (DFT) calculations and quantum theory of atoms in molecule and natural bond orbitals analysis. The complexes are bound by multiple secondary bonding interactions, the most important of which reflects the Lewis ambiphilicity of 1,2,5-chalcogenadiazoles and includes charge transfer from O atoms of the ethers onto E atoms of the chalcogenadiazoles (i.e., chalcogen bonding), and the back-donation from E to O. For complexes of 18-c-6, the DFT-calculated energies of bonding interactions correlate with the melting temperatures of the complexes, as well as with the atomic number of E and the size of the E-associated σ-holes but not with the maximum of molecular electrostatic potential at the σ-holes. Taking into account the previous results, the Lewis ambiphilicity of 1,2,5-chalcogenadiazoles may be used for applications in crystal engineering.

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Section: Introductionmentioning

confidence: 99%

Lewis Ambiphilicity of 1,2,5-Chalcogenadiazoles for Crystal Engineering: Complexes with Crown Ethers

Chulanova

Radiush

Shundrina

et al. 2020

Crystal Growth & Design

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“…The maximum wavelength of luminescence shifted from 585 to 660 nm for 1a , 594 to 761 nm for 1b , and from 580 to 806 nm for 1c . As it was demonstrated, the early [ 23 , 24 ] replacement of heteroatom O on Se led to a reduction in the HOMO-LUMO energy gap from 2.05 to 1.81 eV and, therefore, absorption and emission maximum redshifts took place. On the contrary, λ em was still the same for 1b compounds dissolved in the nonpolar cyclohexane (see Table 3 ).…”

Section: Resultsmentioning

confidence: 99%

Novel D-A-D Fluorescent Dyes Based on 9-(p-Tolyl)-2,3,4,4a,9,9a-hexahydro-1H-carbazole as a Donor Unit for Solution-Processed Organic Light-Emitting-Diodes

et al. 2021

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New fluorescent D-A-D dyes containing 9-(p-tolyl)-2,3,4,4a,9,9a-hexahydro-1H-carbazole as a donor unit and 2,1,3-benzochalcogenadiazoles as an electron-withdrawing group were synthesized. The photoluminescent and electroluminescent properties of novel dyes for fluorescent OLED application were investigated. It was demonstrated that the replacement of lightweight heteroatoms by heavier ones enables the fine tuning of the maximum emission without significantly reducing the luminescence quantum yield. The maximum quantum yield value of 62.6% for derivatives based on 2,1,3-benzoxadiazole (1a) in cyclohexane was achieved. Two devices with the architecture of glass/ITO/PEDOT-PSS/poly-TPD/EML/TPBi/LiF/Al (EML = emitting layer) were fabricated to check the suitability of the synthesized compounds as a single active emission layer in OLED. These OLEDs exhibited clear red electroluminescence of the dyes with the maximum current efficiency of 0.85 Cd/A.

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“…Furthermore, a comparatively studied and reported candlelight organic LEDs showing their fabrication method, color temperature, power efficacy, current efficacy, and the respective references are revealed in Table S2. The reported color temperature (at 100 cd/m 2 ) for the solution and dry-processed candlelight organic LED devices against current efficacy and power efficacy [2,4,5,7,11,12,17,18,21,64,65].…”

Section: Comparison Between the Studied Very Low Color-temperature Candlelight Organic Led And Commercial Luminairesmentioning

confidence: 99%

“…Figure7. The reported color temperature (at 100 cd/m 2 ) for the solution and dry-processed candlelight organic LED devices against current efficacy and power efficacy[2,4,5,7,11,12,17,18,21,64,65].…”

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confidence: 99%

Highly Efficient Candlelight Organic Light-Emitting Diode with a Very Low Color Temperature

et al. 2021

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Low color temperature candlelight organic light-emitting diodes (LEDs) are human and environmentally friendly because of the absence of blue emission that might suppress at night the secretion of melatonin and damage retina upon long exposure. Herein, we demonstrated a lighting device incorporating a phenoxazine-based host material, 3,3-bis(phenoxazin-10-ylmethyl)oxetane (BPMO), with the use of orange-red and yellow phosphorescent dyes to mimic candlelight. The resultant BPMO-based simple structured candlelight organic LED device permitted a maximum exposure limit of 57,700 s, much longer than did a candle (2750 s) or an incandescent bulb (1100 s) at 100 lx. The resulting device showed a color temperature of 1690 K, which is significantly much lower than that of oil lamps (1800 K), candles (1900 K), or incandescent bulbs (2500 K). The device showed a melatonin suppression sensitivity of 1.33%, upon exposure for 1.5 h at night, which is 66% and 88% less than the candle and incandescent bulb, respectively. Its maximum power efficacy is 23.1 lm/W, current efficacy 22.4 cd/A, and external quantum efficiency 10.2%, all much higher than the CBP-based devices. These results encourage a scalable synthesis of novel host materials to design and manufacture high-efficiency candlelight organic LEDs.

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A novel candle light-style OLED with a record low colour temperature

Abstract: Candle light-style OLEDs based on new D–A–π–A type molecules incorporated into Alq3 matrix were developed. A record low color temperature of 1722 K OLED radiation was achieved, which is by 80 K lower than that of the best devices reported previously.

Cited by 22 publications

References 29 publications

Lewis Ambiphilicity of 1,2,5-Chalcogenadiazoles for Crystal Engineering: Complexes with Crown Ethers

Lewis Ambiphilicity of 1,2,5-Chalcogenadiazoles for Crystal Engineering: Complexes with Crown Ethers

Novel D-A-D Fluorescent Dyes Based on 9-(p-Tolyl)-2,3,4,4a,9,9a-hexahydro-1H-carbazole as a Donor Unit for Solution-Processed Organic Light-Emitting-Diodes

Highly Efficient Candlelight Organic Light-Emitting Diode with a Very Low Color Temperature

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