Structural tuning of ancillary chelate in tri-carboxyterpyridine Ru(<scp>ii</scp>) sensitizers for dye sensitized solar cells

Chou, Chien-Chang; Chen, Pei-Hua; Hu, Fa-Chun; Chi, Yun; Ho, Shu‐Te; Jia, Kai; Liu, Shih-Hung; Chou, Pi‐Tai

doi:10.1039/c3ta14876a

Cited by 26 publications

(15 citation statements)

References 74 publications

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“…Amongt he sensitizers tested, TF-24 and TF-28 were assembled with the ancillary of least electron-donatingc haracter (tzzp4) with E 0 ox = 0.96 Va nd of the highest optical response (pzzp6.2) owing to the presence of an additional EDOTfragment, respectively.A se xpected, the corresponding DSSC performances were recorded to be J SC = 17.6 mA cm À2 , V OC = 750 mV,F F = 0.68, and h = 9.04 %f or TF-24, [66] and J SC = 18.1 mA cm À2 , V OC = 660 mV,F F = 0.73, and h = 8.72 %f or TF-28, respectively. [70] These data agree with the factthat the electron-deficient ancillary reduces the electron density at the Ru II metal center,i n which the positive E 0 ox is responsible for the fast regeneration of the oxidized sensitizer.M oreover,a so bserved for TF-28, ab etter optical response is equally important for obtaining efficient DSSC devices. Finally,r eplacement of the tz fragment of TF-24 with ac arboxylate group afforded sensitizer FT-117.…”

Section: -Pyrazolyl-6-phenylpyridine (Pzpp)supporting

confidence: 78%

“…These cyclometalatinga ncillaries were prepared by means of the multistep protocols provided in the literature, [66,70] in which pzpp6.1a nd pzpp6.2 weref urther functionalized with R = 5hexylthien-2-yl and 7-hexylethylenedioxothien-2yl on pzpp6, respectively.A fter that, the desired bis-tridentate Ru II sensitizers were synthesized by coupling these ancillaries with [Ru(tectpy)Cl 3 ]( tectpy = 4,4',4''-triethoxycarboxy-2,2':6',2''-terpyridine), followed by standard separation and base-catalyzed hydrolysis. Amongt he sensitizers tested, TF-24 and TF-28 were assembled with the ancillary of least electron-donatingc haracter (tzzp4) with E 0 ox = 0.96 Va nd of the highest optical response (pzzp6.2) owing to the presence of an additional EDOTfragment, respectively.A se xpected, the corresponding DSSC performances were recorded to be J SC = 17.6 mA cm À2 , V OC = 750 mV,F F = 0.68, and h = 9.04 %f or TF-24, [66] and J SC = 18.1 mA cm À2 , V OC = 660 mV,F F = 0.73, and h = 8.72 %f or TF-28, respectively.…”

Section: -Pyrazolyl-6-phenylpyridine (Pzpp)mentioning

confidence: 99%

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Ruthenium and Osmium Complexes That Bear Functional Azolate Chelates for Dye‐Sensitized Solar Cells

Chi

Wei

2015

Chemistry An Asian Journal

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The preparation of sensitizers for dye-sensitized solar cells (DSSCs) represents an active area of research for both sustainability and renewable energy. Both Ru(II) and Os(II) metal sensitizers offer unique photophysical and electrochemical properties that arise from the intrinsic electronic properties, that is, the higher propensity to form the lower-energy metal-to-ligand charge-transfer (MLCT) transition, and their capability to support chelates with multiple carboxy groups, which serve as a bridge to the metal oxide and enable efficient injection of the photoelectron. Here we present an overview of the synthesis and testing of these metal sensitizers that bear functional azolate chelates (both pyrazolate and triazolate), which are capable of modifying the metal sensitizers in a systematic and beneficial manner. Basic principles of the molecular designs, the structural relationship to the photophysical and electrochemical properties, and performances of the as-fabricated DSSCs are highlighted. The success in the breakthrough of the synthetic protocols and potential applications might provide strong stimulus for the future development of technologies such as DSSCs, organic light-emitting diodes, solar water splitting, and so forth.

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Section: -Pyrazolyl-6-phenylpyridine (Pzpp)supporting

confidence: 78%

Section: -Pyrazolyl-6-phenylpyridine (Pzpp)mentioning

confidence: 99%

Ruthenium and Osmium Complexes That Bear Functional Azolate Chelates for Dye‐Sensitized Solar Cells

Chi

Wei

2015

Chemistry An Asian Journal

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“…Commercially available reagents were used without further purification unless otherwise stated. The imidazolium derivatives, i.e., 3‐(4‐fluorophenyl)‐1‐methyl‐1H‐Imidazolium imMeH(PF 6 ) and 1,3‐bis(4‐fluorophenyl)‐1H‐Imidazolium imArH(PF 6 ) were synthesized according to the literature methods, while the dianionic 2‐pyrazolyl‐6‐phenyl pyridine chelate, e.g., pzpy CF3 ph Bu (L1H 2 ), pzpyph Bu (L2H 2 ) and pzpy Bu ph FO (L3H 2 ), were prepared using the multi‐step protocol depicted in literature . 1 H and 19 F NMR spectra were measured with a Varian Mercury‐400 instrument.…”

Section: Methodsmentioning

confidence: 99%

Luminescent Diiridium Complexes with Bridging Pyrazolates: Characterization and Fabrication of OLEDs Using Vacuum Thermal Deposition

Liao

Rajakannu

Gnanasekaran

et al. 2018

Advanced Optical Materials

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efficient and durable emitters that are capable to show RGB colors constitute one of the key components for the successful advancement of OLED technology. [1] However, development of metal based phosphorescent emitters, particularly the blue-emitting phosphors, is still far from success in term of emission efficiency and chemical stability. [2] This is attributed to the higher energy demanded for the excited states of blue-emitting phosphors versus those of the lower-energy green and red emitters, so that the blue emitters are more subject to the upper lying metal-centered dd excited state via thermal population, causing quenching and faster decomposition at the long-lived triplet states. [3] Both scenarios are expected in giving emitters with inadequate efficiency and stability, which account for the grand challenges in the design of metal based phosphors.The majority of metal based OLED phosphors were mononuclear Ir(III) metal complexes bearing three bidentate chelates in either homoleptic and heteroleptic modes, among which the representative examples are [Ir(ppy) 3 ] [4] and MS-2 [5] (Scheme 1, top); both possess the class of phenylpyridinato cyclometalates. According to the chemical thermodynamics, however, these tris-bidentate complexes are expected to be less stable compared to the emitters bearing A series of novel diiridium complexes (1-4) bearing both functional 2-pyrazolyl-6-phenyl pyridine chelate and bidentate phenyl imidazolylidene chelate are synthesized, for which the pyrazolate fragment of the tridentate 2-pyrazolyl-6-phenyl pyridine also behaves as the bridge to hold two iridium atoms in close vicinity. Their structure is unambiguously confirmed using X-ray structure determination on the corresponding derivative 2a bearing 1,3-bis(4-fluorophenyl)-1H-Imidazolyl cyclometalate. Their photophysical and electrochemical properties are studied and further affirmed by the computational approaches. All these Ir(III) metal complexes 1-4 are very stable in both solution and solid film with near unity emission quantum efficiency. As opposed to most of diiridium complexes documented in literature, 1-4 are volatile and suitable for fabrication of organic light emitting diodes (OLEDs) under vacuum evaporation. The corresponding electroluminescent devices exhibit superior performance, among which external quantum efficiency of 27.6% using 2 as dopant stands for the record high of OLEDs using dinuclear Ir(III) complexes. They also offer a low roll-off at high luminance, demonstrating their potential en route to high performance OLEDs.

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“…Recently, our endeavors targeted at the DSC research have led to the isolation of a newer class of panchromatic, chargeneutral sensitizers with both bi-and tridentate ancillaries, such as pyridyl azolate, [16] 2,6-diazolyl pyridine, [17] and 2-azolyl-6-phenylpyridine, [18,19] to replace either p-accepting thiocyanate ancillaries or difluorophenyl pyridinato cyclometalates and their analogues. [20] All of these azolate-containing Ru II sensitizers have showed respectable cell performance characteristics versus typical Ru II -based metal sensitizers, [2b, 21] under fabrication conditions that used an I À /I 3 À -based liquid electrolyte.…”

Section: Introductionmentioning

confidence: 99%

Thiocyanate‐Free Ruthenium(II) Sensitizers for Dye‐Sensitized Solar Cells Based on the Cobalt Redox Couple

Wu¹,

Clifford²,

Wang³

et al. 2014

ChemSusChem

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Two thiocyanate-free ruthenium(II) sensitizers, TFRS-41 and TFRS-42, with distinctive dialkoxyphenyl thienyl substituents were successfully prepared and tested for potential applications in making dye-sensitized solar cells (DSCs). Subsequent device fabrication was conducted by using a [Co(bpy)3 ](2+/3+) -based (bpy=2,2'-bipyridine) electrolyte, for which the best performance data, namely, JSC =13.11 mA cm(-2) , VOC =862 mV, fill factor=0.771, and η=8.71%, were recorded for the sensitizer TFRS-42 with a 2,6-dialkoxyphenyl substituent under AM 1.5G irradiation. The markedly higher Voc value was confirmed by the longer electron lifetime revealed in transient photovoltage (TPV) measurements versus the TFRS-1 sensitizer. In addition, DFT calculation and detailed first-principles computational analysis were conducted to provide a rationale for the observed trends in their photovoltaic performances and electron lifetimes, with reference to different performances exhibited by three thiocyanate-free sensitizers, TFRS-1, TFRS-41 and TFRS-42, versus Z907 reference. Through the proper control of peripheral substituents, the thiocyanate-free ruthenium(II)-based DSC sensitizers can positively influence the performances of DSCs, with better light-harvesting capability and suppressed charge recombination, for DSC cells fabricated by using a [Co(bpy)3 ](2+/3+) -based electrolyte.

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Structural tuning of ancillary chelate in tri-carboxyterpyridine Ru(ii) sensitizers for dye sensitized solar cells

Abstract: Systematically changing the ancillary chelate from L3 to L6, together with addition of a 3,4-ethylenedioxythiophene (EDOT) appendage, boosts the overall efficiencies of a fabricated DSC device.

Cited by 26 publications

References 74 publications

Ruthenium and Osmium Complexes That Bear Functional Azolate Chelates for Dye‐Sensitized Solar Cells

Ruthenium and Osmium Complexes That Bear Functional Azolate Chelates for Dye‐Sensitized Solar Cells

Luminescent Diiridium Complexes with Bridging Pyrazolates: Characterization and Fabrication of OLEDs Using Vacuum Thermal Deposition

Thiocyanate‐Free Ruthenium(II) Sensitizers for Dye‐Sensitized Solar Cells Based on the Cobalt Redox Couple

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