173063-52-0Relevant articles and documents
4H-1,2,6-Thiadiazin-4-one-containing small molecule donors and additive effects on their performance in solution-processed organic solar cells
Hermerschmidt, Felix,Kalogirou, Andreas S.,Min, Jie,Zissimou, Georgia A.,Tuladhar, Sachetan M.,Ameri, Tayebeh,Faber, Hendrik,Itskos, Grigorios,Choulis, Stelios A.,Anthopoulos, Thomas D.,Bradley, Donal D. C.,Nelson, Jenny,Brabec, Christoph J.,Koutentis, Panayiotis A.
, p. 2358 - 2365 (2015)
The optical, electrochemical, morphological and transport properties of a series of thiadiazinone (acceptor) and (thienyl)carbazoles (donor) containing π-extended donor-acceptor-donors (D-A-D) are presented. Systematic variations in the number of the thienyl units, the choice of branched or straight alkyl side chains and the use of a processing additive demonstrate their use as electron donors in bulk heterojunction solar cells blended with fullerene acceptors. The best power conversion efficiency (PCE) of 2.7% is achieved by adding to the D-A-D 3:fullerene blend a polydimethylsiloxane (PDMS) additive, that improves the morphology and doubles the hole mobility within the D-A-D:fullerene blend.
Phenothiazine Decorated Carbazoles: Effect of Substitution Pattern on the Optical and Electroluminescent Characteristics
Konidena, Rajendra Kumar,Thomas, K. R. Justin,Kumar, Sudhir,Wang, Ya-Chi,Li, Chieh-Ju,Jou, Jwo-Huei
, p. 5812 - 5823 (2015)
A series of thienylphenothiazine decorated carbazoles were synthesized and characterized by optical, electrochemical, thermal, and theoretical investigations. Absorption spectra of the compounds are influenced by the substitution pattern and chromophore number density. Compounds containing 2,7-substitution exhibited red-shifted absorption, while the chromophore loading on the other positions led to the increment in molar extinction coefficients due to the increase in the chromophore density. Multiple substitutions resulted in twisting of chromophores and affected the conjugative delocalization of the -electrons, which produced shorter wavelength absorption for the 2,3,6,7-tetrasubstituted derivative. Interestingly, the compounds exhibited excited-state solvatochromism attributable to the structural reorganization-induced electronic perturbations. The solvatochromic data are supportive of a general solvent effect, which is further confirmed by Lippert-Mataga correlation. End-capping with butterfly shaped phenothiazine restrained the formation of molecular aggregates in the solid state. All of the compounds displayed exceptional thermal stability attributable to the rigid carbazole building block. Solution processed OLED fabricated using the new materials as emitting dopants in 4,4′-bis(9H-carbazol-9-yl)biphenyl host exhibited bluish green electroluminescence.
Multinuclear 2-(Quinolin-2-yl)quinoxaline-Coordinated Iridium(III) Complexes Tethered by Carbazole Derivatives: Synthesis and Photophysics
Zhu, Xiaolin,Liu, Bingqing,Cui, Peng,Kilina, Svetlana,Sun, Wenfang
, p. 17096 - 17108 (2020)
Five mono/di/trinuclear iridium(III) complexes (1-5) bearing the carbazole-derivative-tethered 2-(quinolin-2-yl)quinoxaline (quqo) diimine (N^N) ligand were synthesized and characterized. The photophysical properties of these complexes and their corresponding diimine ligands were systematically studied via UV-vis absorption, emission, and transient absorption (TA) spectroscopy and simulated by time-dependent density functional theory. All complexes possessed strong well-resolved absorption bands at 400 nm that have predominant ligand-based 1π,π? transitions and broad structureless charge-transfer (1CT) absorption bands at 400-700 nm. The energies or intensities of these 1CT bands varied pronouncedly when the number of tethered Ir(quqo)(piq)2+ (piq refers to 1-phenylisoquinoline) units, πconjugation of the carbazole derivative linker, or attachment positions on the carbazole linker were altered. All complexes were emissive at room temperature, with 1-3 showing near-IR (NIR) 3MLCT (metal-to-ligand charge-transfer)/3LLCT (ligand-to-ligand charge-transfer) emission at ～710 nm and 4 and 5 exhibiting red or NIR 3ILCT (intraligand charge-transfer)/3LMCT (ligand-to-metal charge-transfer) emission in CH2Cl2. In CH3CN, 1-3 displayed an additional emission band at ca. 590 nm (3ILCT/3LMCT/3MLCT/3π,π? in nature) in addition to the 710 nm band. The different natures of the emitting states of 1-3 versus those of 4 and 5 also gave rise to different spectral features in their triplet TA spectra. It appears that the parentage and characteristics of the lowest triplet excited states in these complexes are mainly impacted by the πsystems of the bridging carbazole derivatives and essentially no interactions among the Ir(quqo)(piq)2+ units. In addition, all of the diimine ligands tethered by the carbazole derivatives displayed a dramatic solvatochromic effect in their emission due to the predominant intramolecular charge-transfer nature of their emitting states. Aggregation-enhanced emission was also observed from the mixed CH2Cl2/ethyl acetate or CH2Cl2/hexane solutions of these ligands.
Synthesis of Poly[N-(2-ethylhexyl)-3,6-carbazole-alt-aniline] Copolymer and Its Potential as Hole-Transporting Material to Solid-State Dye-Sensitized Solar Cells
Nguyen, Van Nga,Kwon, Younghwan
, p. 53 - 61 (2019)
In this study, thermally stable and solution-processable conjugated poly[N-(2-ethylhexyl)-3,6-carbazole-alt-aniline] copolymer containing alternating carbazole and triarylamine moieties in the polymer backbone was synthesized in a good yield by Pd-catalyzed polycondensation. The polymer exhibited maximum UV-vis absorption peak at 309 nm and maximum photoluminescence peak at 452 nm. From the optical and electrochemical characterization, the band gap, HOMO, and LUMO energy levels of the polymer were measured to be 2.91 eV, -5.19 eV, and -2.28 eV, respectively. The polymer was used to examine the hole-transporting performance to a solid-state dye-sensitized solar cell (ssDSSC). The ssDSSC fabricated with poly[N-(2-ethylhexyl)-3,6-carbazole-alt-aniline] copolymer showed a PCE of 1.50% with Jsc = 3.76 mA/cm2, Voc = 538 mV, and FF = 74.3%, implying the potential of the synthesized polymer as a hole-transport material (HTM) to ssDSSC.
Photophysics and non-linear absorption of Au(i) and Pt(ii) acetylide complexes of a thienyl-carbazole chromophore
Goswami, Subhadip,Wicks, Geoffrey,Rebane, Aleksander,Schanze, Kirk S.
, p. 17721 - 17728 (2014)
In order to understand the photophysics and non-linear optical properties of carbazole containing π-conjugated oligomers of the type ET-Cbz-TE (E = ethynylene, T = 2,5-thienylene, Cbz = 3,6-carbazole), a detailed investigation was carried out on a series of oligomers that feature Au(i) or Pt(ii) acetylide end groups , as well as a Pt(ii)-acetylide linked polymer (CBZ-Au-1 and CBZ-Pt-1, CBZ-Poly-Pt). These organometallic chromophores were characterized by UV-visible absorption and variable temperature photoluminescence spectroscopy, nanosecond transient absorption spectroscopy, open aperture nanosecond z-scan and two photon absorption (2PA) spectroscopy. The Au(i) and Pt(ii) oligomers and polymer exhibit weak fluorescence in fluid solution at room temperature. Efficient phosphorescence is observed from the Pt(ii) systems below 150 K in a solvent glass; however, the Au(i) oligomer exhibits only weak phosphorescence at 77 K. Taken together, the emission results indicate that the intersystem crossing efficiency for the Pt(ii) chromophores is greater than for the Au(i) oligomer. Nonetheless, nanosecond transient absorption indicates that direct excitation affords moderately long-lived triplet states for all of the chromophores. Open aperture z-scan measurement shows effective optical attenuation can be achieved by using these materials. The 2PA cross section in the degenerate S0→S1 transition region was in the range 10-100 GM, and increased monotonically toward shorter wavelengths, reaching 800-1000 GM at 550 nm.
Visible-light driven photocatalytic oxygen evolution reaction from new poly(phenylene cyanovinylenes)
Mansha, Muhammad,Khan, Ibrahim,Ullah, Nisar,Qurashi, Ahsanulhaq,Sohail, Manzar
, p. 95 - 102 (2017)
Two new n-type conjugated polymers, poly(N-(2-ethylhexyl)-3,6-carbazole-p-bis(2-ethylhexyloxy)-phenylene cyanovinylene) (P1) and poly(N-(2-ethylhexyl)-3,6-carbazole-p-bisdodecyloxy-phenylene cyanovinylene) (P2) were synthesized and explored for their photo-electrochemical catalytic activity for oxygen evolution reaction (OER). When these polymers were used as photoanodes under visible light irradiation, oxygen evolution occurred at over potential as low as?+0.6?V vs. SCE. In the chronoamperometric (CA) measurements, the photo-current density generated at?+0.6?V by P1 and P2 was 0.31 and 0.27?μA/cm2, respectively. This is an excellent performance of a metal free and without the use of sacrificial electron donors polymer photoanodes. The higher photoelectrochemical (PEC) performance of P1 was attributed to its narrow band gap and larger surface area. Moreover, the drastic quenching of the photoluminescence (PL) emission intensity of P1 suggested the recombination of charges was effectively suppressed, which is in excellent agreement with our experimental observations. In the linear sweep voltammetry (LSV) measurements, the onset potential was observed at around 0.73?V whereas the maximum current densities by P1 and P2 were realized at 0.39?mA/cm2 and 0.15?mA/cm2, respectively. Long-term stability testing via CA indicated that P1 was more stable than P2, which warranted its potential as photocatalyst for solar water splitting. In addition, the optical band gaps of P1 and P2, derived from the onset absorption edge, were found to be 2.51 and 2.62?eV, respectively, and the band gaps measured by Kubelka?Munk (KM), cyclic voltammetry (CV) and computational methods were found to be consistent. These polymers are readily soluble in common organic solvents which make them potential candidates for photovoltaic devices application.
Synthesis of an A-D-A type of molecule used as electron acceptor for improving charge transfer in organic solar cells
Zhang, Chao-Zhi,Gu, Shu-Duo,Shen, Dan,Yuan, Yang,Zhang, Mingdao
, p. 104 - 111 (2016)
Electron-accepting molecules play an important role in developing organic solar cells. A new type of A-D-A molecule, 3,6-di([7-(5-bromothiophen-2-yl)-1,5,2,4,6,8-dithiotetrazocin-3-yl]thiophen-2-yl)-9-(2-ethylhexyl)carbazole, was synthesized. The lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels are ?3.55 and ?5.85 eV, respectively. Therefore, the A-D-A type of compound could be used as electron acceptor for fabricating organic solar cell with a high open circuit voltage. Gibbs free energy (?49.2 kJ/mol) reveals that the process of A-D-A acceptor accepting an electron from poly(3-hexylthiophene) at excited state is spontaneous. The value of entropy (118 J/mol) in the process of an electron transferring from P3HT to the A-D-A acceptor at organic interface suggests that electrons generated from separation of electron-hole pairs at donor/acceptor interface would be delocalized efficiently. Therefore, the A-D-A molecule would be a potential acceptor for efficient organic BHJ solar cells.
Hyperbranched fluorene-alt-carbazole copolymers with spiro[3.3]heptane-2,6-dispirofluorene as the core and their application in white polymer light-emitting devices
Wu, Yuling,Li, Jie,Liang, Wenqing,Yang, Junli,Sun, Jing,Wang, Hua,Liu, Xuguang,Xu, Bingshe,Huang, Wei
, p. 49662 - 49670 (2015)
A series of hyperbranched copolymers with fluorene-alt-carbazole as the branches and three-dimensional-structured spiro[3.3]heptane-2,6-dispirofluorene (SDF) as the core were synthesized by one-pot Suzuki polycondensation. 4,7-Dithienyl-2,1,3-benzothiadiazole (DBT) as the orange-light emitting unit was introduced into the backbones to obtain white-light emission. The thermal, photoluminescent (PL), electrochemical and electroluminescent (EL) properties of the copolymers were investigated. The copolymers show great thermal stabilities by the introduction of a carbazole moiety. Besides, the HOMO energy levels of the copolymers were enhanced and the hole injection was improved because of the hole-transporting ability of the carbazole unit. The hyperbranched structures suppress the interchain interactions efficiently, and help to form amorphous films. The copolymers exhibit efficient EL performance as a result of the hyperbranched structure with the incorporation of the carbazole moiety. A quite low turn-on voltage of 5.3 V, a maximal luminance of 7409.5 cd m-2 and a luminous efficiency of 4.27 cd A-1 were achieved with a CIE coordinate of (0.32, 0.26) for the PFCzSDF10DBT10 (10 mol% of SDF and 0.1 mol% of DBT) device. The hyperbranched framework based on fluorene-alt-carbazole branches and SDF core are attractive candidates for solution-processable white polymer light-emitting device (WPLED) applications.
3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic-organic hybrid perovskite solar cells
Li, Wei,Otsuka, Munechika,Kato, Takehito,Wang, Yang,Mori, Takehiko,Michinobu, Tsuyoshi
, p. 1401 - 1408 (2016)
The ever increasing demand for clean energy has encouraged researchers to intensively investigate environmentally friendly photovoltaic devices. Inorganic-organic hybrid perovskite solar cells (PSCs) are very promising due to their potentials of easy fabrication processes and high power conversion efficiencies (PCEs). Designing hole-transporting materials (HTMs) is one of the key factors in achieving the high PCEs of PSCs. We now report the synthesis of two types of carbazole-based polymers, namely 3,6-Cbz-EDOT and 2,7-Cbz-EDOT, by Stille polycondensation. Despite the same chemical composition, 3,6-Cbz-EDOT and 2,7-Cbz-EDOT displayed different optical and electrochemical properties due to the different connectivity mode of the carbazole unit. Therefore, their performances as hole-transporting polymeric materials in the PSCs were also different. The device based on 2,7-Cbz-EDOT showed better photovoltaic properties with the PCE of 4.47% than that based on 3,6-Cbz-EDOT. This could be due to its more suitable highest occupied molecular orbital (HOMO) level and higher hole mobility.
A-π-D-π-A carbazole derivatives with remarkable solvatochromism and mechanoreponsive luminescence turn-on
Wen, Ping,Gao, Zhixiang,Zhang, Rong,Li, Anran,Zhang, Fang,Li, Jie,Xie, Jingjuan,Wu, Yuezhen,Wu, Min,Guo, Kunpeng
, p. 6136 - 6143 (2017/07/11)
Two A-π-D-π-A molecules with a carbazole donor and a dicyanovinyl acceptor but differing in N-hexyl (h-CPDM) and N-isooctyl substituents (i-CPDM) were synthesized, and both of them presented remarkable dual properties of solvatochromism and mechanoresponsive luminescence (MRL) turn-on. The intrinsic intramolecular charge transfer (ICT) characteristic endowed both luminophors with a prominent solvatochromic effect, with emission color tuning from blue to orange-red by changing the solvent from nonpolar hexane to polar dimethyl sulfoxide. Meanwhile, the non-/weakly emissive original powders of h-CPDM and i-CPDM gave bright orange (610 nm) and yellow (596 nm) emission with the photoluminescence quantum yields increasing as high as 85-fold after being ground. Investigations revealed this mechanoresponsive luminescence turn-on could be ascribed to the disturbance of the π-π stacking interactions in the non-/weakly emissive J-aggregates by mechanical force. This work offers carbazole derivatives that can be used as sensitive fluorescent indicators for organic solvents and mechanical sensors.
