Jung Il-Woo Emissions Et Séries Tv

The international Telecommunication syndicat announced a nouveau color gamut étendard of broadcast prestations de service television (BT 2020) pour ultra-high-definition la télé in 2012. To satisfy auto wide-color gamut défaut of BT 2020, monochromatic red (R), green (G), et blue (B) emissions need a petit full broad at half-maximum, which is an important property for improving shade purity. Although essential light-emitting diode (OLED) displays are right now one du the henchmen types de display technologies, their broad emission dessus strong vibronic coupling in between ground et excited states is a principale hurdle à overcome in auto development ns next-generation wide-color gamut displays. Thus, auto development du OLED emitters with narrowband R–G–B emissions is ns great significance. In this review, thé recent progress in auto development de OLED materials with narrowband emissions is summarized by grouping them right into fluorescent, phosphorescent, et thermally activated delayed fluorescent emitters à reveal auto correlation in between molecular structures, optical properties, et device characteristics. Nous discuss reasonable molecular design strategies to achieve narrow photoluminescence and electroluminescence and the underlying mechanisms pour controlling the emission bandwidth. Finally, the challenges in thé realization of wide-color gamut oled displays et the a venir prospects of such gadgets are discussed.

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Since the first organic light-emitting diode (OLED) was effectively demonstrated par Tang and Slyke in 19871, OLEDs oui been generally studied in both academia et industry, becoming a mainstream display modern technology in full-color televisions and smartphones. They ont various advantages, such as a light weight, fast réagir time, broad viewing angle, facile chemical tunability du emitting molecules, low energy consumption, compatibility with flexible plastic substrates, et form factors for various types de displays2. Based conditions météorologiques the light-emitting mechanisms, different types du OLEDs oui been developed: fluorescence (1st generation)-based, phosphorescence (2nd generation)-based, et thermally caused delayed fluorescence (TADF, third generation)-based OLEDs3. Recently, extensive research nous the fourth generation du OLEDs is in progress venir improve auto device efficiency, lifetime, et color purity in particular. Despite the many advantages de OLEDs, their emission spectra often montrer broad bandwidths, i m sorry are extremely detrimental to achieving high shade purity parce que le future high-end display screen electronics such ont high-definition TV and ultra-high-definition tv (UHDTV).

The “CIE (International frais on Illumination) 1931 color space” was first defined based nous tristimulus values; then, auto modified CIE 1976 was announced, et both CIE 1931 et 1976 became thé most commonly accepted normes to define emission couleurs in auto field de displays4. Auto CIE coordinate visualizes the entire variety of couleurs that have the right to be obtained de mixing auto three primary couleurs (red (R), vert (G), and blue (B)) passant par varying auto wavelength and emission intensity. In 2012, the international Telecommunication union (ITU) announced a new color gamut défaut for UHDTVs called the Broadcast service Television 2020 (BT 2020) (Fig. 1)5. Compared to thé previously report BT 709, the color gamut became more comprehensive with CIE coordinates à la the R, G, et B couleurs of (0.708, 0.292), (0.170, 0.797), and (0.131, 0.046), respectively. This échanger was made because ns the cultivation demand for monochromatic R, G, and B couleurs to improve shade purity (Fig. 1a) 6.


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a Comparison de BT 709 and BT 2020 in CIE 1931; expanded shade gamut with auto vertices thrust to the parabolic edge in BT 2020. b auto color gamut becomes broader with decreasing emission bandwidth. c Recent viewpoints in auto development of organic light-emitting materials with narrowband emission based nous fluorescent, phosphorescent, and TADF emitters. d Summary de FWHM and EQE values de EL spectra versus emission wavelength for fluorescent (black), phosphorescent (blue), and TADF (red) emitters.

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Vibronic coupling in fluorescent and phosphorescent necessary emitters between auto singlet soil state (S0) et the singlet (S1), jaune triplet (T1) excited states together with calculé transfer (CT) interactions often induces broad peaks in both photoluminescence (PL) et electroluminescence (EL) spectra, showing a full width at half-maximum (FWHM) du over 70 nm7,8,9,10,11. Organic emitters show significantly more comprehensive emission spectra than inorganic quantum dots (QDs) and perovskite-based emitters, limiting the potential for OLEDs with the high color purity proposed de BT 202012. Thus, thé development ns OLED emitters v narrowband R, G, et B emissions v extremely petit FWHM is du paramount importance. Oui seen in Fig. 1b, thé color gamut becomes wider with to decrease FWHM values in thé emission spectra, satisfying the color gamut défaut of BT 202013,14.

In this review, conditions météorologiques summarize current developments and important studies ns organic light-emitting materials et devices v narrowband emission. Nous categorize this materials et devices based conditions météorologiques their emissions mechanism passant par grouping them into fluorescent, phosphorescent, and TADF emitters (Fig. 1c). Since there is currently ne sont pas clear definition du “narrow emission”, we mainly focused conditions météorologiques recent reports de OLED materials with a FWHM smaller than 50 nm in your emission spectra (Fig. 1d). Reasonable molecular conception strategies to achieve small PL et EL emission et the related electronic structure and light-emitting characteristics, including auto resulting maker properties, space discussed to understand auto underlying mechanisms à la controlling auto emission bandwidth. Finally, we provide our perspective on the remaining challenges in this research area that must be overcome à develop the suivant generation ns wide-color gamut old displays.


π-Conjugated essential fluorophores experience from limite color purity périmé to their large emission spectra originating from thé intrinsic vibronic coupling et structural relaxation du the S1 state (Fig. 2a). Venir achieve narrow EL spectra through a small FWHM, color filters et optical microcavities oui been thought about in the fabriquer of fluorescent OLEDs15,16,17. However, the development of efficace organic fluorescent emitters through narrow emission bandwidths parce que le high shade purity remains an important goal. Ont shown in Fig. 2b, the relatif intensity (I0-1/I0-0) of the 0–0 (between auto ν = 0 vibrational levels ns S0 et S1) et 0–1 (from ν = 0 ns S1 venir ν = 1 de S0) vibronic transitions is determined par the Huang–Rhys aspect (S)18. When π-conjugated necessary molecules oui a in your ar excited (LE) state v a similar equilibrium geometry to the ground state (structural distortion, ΔQ (approx) 0), a taille orbital overlap results in a dominant 0–0 vibronic transition, converging the ns value venir zero and producing a sharp single emission peak19. In contrast, année increase in ΔQ de the éducation of the CT state deserve to induce a strong contribution from 0 à n (n = 1, 2, 3…) vibronic transitions, resulting in a broader emission peak9,18,20. Thus, the design of rigid structures with a lack ns CT character in the excited state is crucial to to decrease the s value and develop necessary fluorescent products with narrowband emission.

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In this chapter, we se concentrer sur on auto molecular brouillon of narrowband emitting fluorophores et structure-optical residential or commercial property correlations by categorizing the molecules right into (i) twisted structure with bulky substituents through suppressed intermolecular aggregation, (ii) rigid/fused fragrant molecules there is no CT character, (iii) 5,12-dihydroquinolino<2,3-b>acridine-7,14-dione (quinacridone) and (iv) 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) derivatives (Fig. 3). Much ns the vault work worrying fluorescent singlet emitters v narrow emission studied blue-emitting materials et their EL devices. Part quinacridone and BODIPY-based fluorophores oui demonstrated green and red emission spectra with remarkably small FWHM values. Auto narrow emission v a predominant 0–0 vibronic transition can it is in ascribed to the enhanced les character et negligible CT interaction in thé rigid et symmetrical molecule structures. The light-emitting properties ns representative singlet emitters with narrowband emission et their machine characteristics are summarized in Table 1.