Browsing by Author "Chang, Chia-Chih"

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A chlorinated nonacyclic carbazole-based acceptor affords over 15% efficiency in organic solar cells
(2020-01-21)
Chen, Tsung-Wei
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Peng, Kuan-Lin
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Lin, You-Wei
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Su, Yi-Jia
;
Ma, Ko-Jui
In this contribution, a dithienocyclopentacarbazole (DTC)-based and two dithieno[3,2-b]thiophenecyclopentacarbazole (DTTC)-based non-fullerene acceptors (NFAs) named DTC-4F, DTTC-4F and DTTC-4Cl were exploited to elucidate the effects of conjugation extension and end group chlorination. DTTC-4F was designed through conjugation extension on the basis of DTC-4F by fusing one additional thiophene on both flanks of the heptacyclic DTC core, generating the nonacyclic DTTC core. Compared with DTC-4F, DTTC-4F features up-shifted energy levels, red-shifted absorption and enhanced pi-pi interaction. PM6:DTTC-4F exhibits a decent PCE of 13.89% with a V-OC of 0.95 V, a J(SC) of 21.66 mA cm(-2) and a FF of 67.60%. Although DTTC-4F affords a reduced FF compared to DTC-4F, a DTTC-4F-based device delivers a higher PCE than DTC-4F-based devices due to the extended absorption range of DTCC-4F in comparison with DTC-4F. Since chlorinated NFAs are known to possess stronger pi-pi interaction than fluorinated NFAs, DTTC-4Cl was therefore synthesized by end-capping DTTC core with 2Cl-IC groups instead of 2F-IC groups. Moreover, DTTC-4Cl demonstrates a red-shifted absorption in comparison with DTTC-4F, which is beneficial for light-harvesting. Overall, PM6:DTTC-4Cl affords an outstanding PCE of 15.42% with a V-OC of 0.92 V, a J(SC) of 22.64 mA cm(-2) and a FF of 74.04%, which is the record PCE observed in carbazole-based NFAs.
Cross-linked Triarylamine-Based Hole-Transporting Layer for Solution-Processed PEDOT:PSS-Free Inverted Perovskite Solar Cells
(2018-06-27)
Chang, Chia-Chih
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Tao, Jhih-Hao
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Tsai, Che-En
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Cheng, Yen-Ju
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Hsu, Chain-Shu
The device performance of inverted organic metallohalide perovskite solar cells (OMPSCs) is optimized via tailoring the electrode surfaces with electron- and hole-transporting materials. This work demonstrates the fabrication of PEDOT:PSS-free OMPSCs using' a hole-transporting composite material consisting of bilayered vanadium oxide (VOx) and a thermally cross-linked triarylamine-based material X-DVTPD, which contributes to higher V-oc and J(sc) values. The hydrophobicity of X-DVTPD resulted in the formation of large perovskite crystals and enhanced the stability of OMPSCs. Integration of ionic fullerene derivative, fulleropyrrolidinium iodide, in OMPSCs as a hole-blocking interfacial layer at the interface with Ag proves effective to further boost the device efficiency to 18.08%.
Fluorinated heptacyclic carbazole-based ladder-type acceptors with aliphatic side chains for efficient fullerene-free organic solar cells
(2019-05-01)
Chen, Tsung-Wei
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Hsiao, Yu-Tang
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Lin, You-Wei
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Chang, Chia-Chih
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Chuang, Wei-Tsung
Molecular engineering of non-fullerene acceptors (NFAs) is a promising strategy to uncover new structure-property relationships and design principles for developing next-generation high performance n-type materials. Two dithienocyclopentacarbazole (DTC)-based NFAs, DTC(4R)-IC and DTC(4R)-4FIC, are synthesized to elucidate the effects of incorporating aliphatic side chains and 2-(5,6-difluoro-3-oxo-2,3-dihydro-1H-inden-1-ylidene)malononitrile (2FIC) end groups on the thermal and optoelectronic properties of these NFAs. An inverted organic solar cell architecture of ITO/ZnO/J71:NFA/MoO3/Ag is employed. By replacing the phenyl-based side chains with aliphatic side chains on the carbon bridges of the carbazole-based core, the device containing DTC(4R)-IC exhibits an enhanced PCE of 9.61%, a V-OC of 0.94 V, a J(SC) of 16.44 mA cm(-2), and a FF of 62.00%, whereas the device containing DTC(4Ph)-IC exhibits a PCE of 7.76%. The incorporation of 2FIC end groups affords DTC(4R)-4FIC featuring better device performance relative to DTC(4R)-IC, a more red-shifted absorption edge, and a broader absorption range upon fluorination. Notably, the device fabricated with DTC(4R)-4FIC affords a V-oc of 0.82 V, a J(sc) of 18.92 mA cm(-2), a FF of 70.22% and a highest PCE of 10.89%, which is by far the highest PCE for NFA containing heptacyclic carbazole cores.
Morphology-Controlled Fabrication of Co3O4 Catalysts and Performance Towards Low Temperature CO Oxidation
(1970-01-01)
Wu, Ruei-Ci
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Tang, Chih-Wei
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Chang, Moo-Been
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Chang, Chia-Chih
;
Wang, Chih-Chia
This article reports the heterogeneous catalysis of CO oxidation over nanostructured Co3O4 at low temperatures. The hydrothermal method was deftly exploited to fabricate nanostructured Co3O4 with three kinds of precipitants (i.e., urea, hexamethylene tetramine, and sodium hydroxide), which were thoroughly characterized with XRD, BET, TEM/SEM, HR-TEM, H-2-TPR, and XPS to understanding the correlation between the morphology of Co3O4 and the corresponding catalytic performance. Specifically, the straw-like nanorods, flower-like nanosheets, and honeycomb-like nanoparticles of Co3O4 could be controlled with the choice precipitants. Our comprehensive analysis indicated that the straw-like Co3O4 nanorods possessed preferential performance for CO catalytic oxidation among these nanostructured Co3O4 to produce CO2. In addition, the results showed good long-term stability for practical application over the straw-like Co3O4 nanorods and showed no significant decay (the activity maintained 97% conversion) within 50 h at 125 degrees C. The novel insights of low-temperature CO oxidation on nanostructured Co3O4 from this work could hold promise for the development of new strategies and design principles for manufacturing highly active and stable catalysts. [GRAPHICS] .
Porphyrin-Containing Polymer as a Superior Blue Light-Absorbing Additive To Afford High-J(sc) Ternary Solar Cells
(2019-01-09)
Li, Chia-Hua
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Chang, Chia-Chih
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Hsiao, Yu-Hsuan
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Peng, Shih-Hao
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Su, Yi-Jia
Integrating an additional component featuring complementary light absorption into binary polymer solar cells is a superior tactic to ameliorate solar cell efficiency and stability. An appropriate additive not only extends the absorption range but may also facilitate charge separation and transport processes. In this work, we elucidate the effects of incorporating a porphyrin-containing conjugated polymer (PPor-1), which displays absorption in 350-500 nm, into binary PTB7-Th:4TIC and PTB7-Th:ITIC blends, affording devices with an average power conversion efficiency approaching 9%. We successfully demonstrate that PPor-1 can be incorporated as an additive to impart improved J(sc) (up to 19.1 mA cm(-2)).
Rapid Prototyping of an Open-Surface Microfluidic Platform Using Wettability-Patterned Surfaces Prepared by an Atmospheric-Pressure Plasma Jet
(2019-10-08)
Wu, She-Ting
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Huang, Chen-Yu
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Weng, Chih-Chiang
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Chang, Chia-Chih
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Li, Bor-Ran
Open-surface microfluidics is promising in terms of enabling economical and rapid biochemical analysis for addressing challenges associated with medical diagnosis and food safety. To this end, we present a simple and economical approach to develop an open-surface microfluidic platform suitable for facile liquid transport and mixing. Customizable patterns with tailored wettability are deposited using a plasma-assisted deposition technique under atmospheric pressure. The flow of the dispensed liquid is driven by gravity, and the tilting angle of the device determines the extent of mixing. First, a hexamethyldisiloxane film was deposited to create hydrophobic patterns on glass, and then, hydrophilic acrylic acid was deposited by a patterned cardboard mask to construct a channel suitable for forming channels to transport aqueous liquids without the need of an external energy input; the liquid can be confined to designated pathways. Several designs including Y-junctions, serpentine-shaped patterns, splitting channels, and concentration gradient generation patterns are presented. The proposed method can spatially pattern a surface with a hydrophobic/hydrophilic area, which can function as a microfluidic channel, and the surface can be applied in microfluidic devices with other types of substrates.
Rayleigh-Instability-Induced Transformation for Confined Polystyrene Nanotubes Prepared Using the Solvent-Vapor-Induced Wetting Method
(1970-01-01)
Fang, Zhi-Xuan
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Chu, Chien-Wei
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Tsai, Chia-Chan
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Chang, Chun-Wei
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Cheng, Ming-Hsiang
Polystyrene (PS) nanotubes prepared using the solvent-vapor-induced wetting method with anodic aluminum oxide templates are for the first time applied to study the thermal stabilities of polymer nanotubes confined in cylindrical geometries. The morphologies of the PS nanotubes and the corresponding transformed PS nanostructures driven by the Rayleigh instabilities after thermal annealing treatments are characterized by scanning electron microscopy. Morphology diagrams of the Rayleigh-instability-induced nanostructures for PS nanotubes prepared via the solvent-vapor-induced wetting method and the solution wetting method are constructed to study the differences in kinetics for samples using different wetting methods. Slower transformation kinetics for the PS samples prepared by the solvent-vapor-induced wetting method than those prepared by the solution wetting method are observed, indicating the better thermal stabilities and the relatively denser packings of the polymer chains in the nanopores for the PS samples prepared using the solvent-vapor-induced wetting method.
Single-Junction Organic Solar Cell Containing a Fluorinated Heptacyclic Carbazole-Based Ladder-Type Acceptor Affords over 13% Efficiency with Solution-Processed Cross-Linkable Fullerene as an Interfacial Layer
(2019-08-28)
Chen, Tsung-Wei
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Chang, Chia-Chih
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Hsiao, Yu-Tang
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Chan, ChoonKee
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Hong, Ling
In this article, a fluorinated heptacyclic dithienocyclopentacarbazole (DTC)-based non-fullerene acceptor (NFA), DTC(4Ph)-4FIC, is synthesized and blended with J71, PBDB-T, and PBDB-TF, featuring complementary absorption and well-matched energy levels. The DTC(4Ph)-4FIC neat film exhibits face-on preference, whereas the nonfluorinated counterpart, DTC(4Ph)-IC, exhibits edge-on preference; this unique feature owing to fluorination in DTC-based NFAs is observed for the first time. More importantly, DTC(4Ph)-4FIC exhibits improved power conversion efficiencies (PCEs) of 10.92 and 10.41% in J71- and PBDB-T-containing devices, while the devices that employed DTC(4Ph)-IC afford PCEs of 7.76 and 9.48%, respectively. Because PBDB-TF is known to exhibit lower energy levels than J71 and PBDB-T, the corresponding device affords a V-OC of 0.95 V, a J(SC) of 18.29 mA cm(-2), a FF of 75.70%, and a PCE of 13.15%, which is 20 and 26% higher than J71- and PBDB-T-containing devices. Furthermore, the inverted device containing the PBDB-TF:DTC(4Ph)-4FIC blend is fabricated using cross-linkable fullerene (C-PCBSD) as the cathode interlayer, affording a decent PCE of 13.36%, with a V-OC of 0.94 V, a J(SC) of 20.20 mA cm(-2), and a FF of 70.42%.
Synthesis of novel conjugated polymers based on benzo[1,2-d:4,5-d ']-bis([1,2,3]triazole) for applications in organic field-effect transistors
(2019-03-28)
Yeh, Yao-Ming
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Huang, Chiao-Hui
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Peng, Shih-Hao
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Chang, Chia-Chih
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Hsu, Chain-Shu
Novel donor-acceptor (D-A) conjugated polymers based on 4,8-bis(5-bromothiophen-2-yl)-2,6-bis(2-octyldodecyl)-2H-benzo[1,2-d:4,5-d']- bis([1,2,3]triazole)-6-ium-5-ide (BTBBTa) combined with three different electron-donating monomers bithiophene (BT), thieno[3,2-b]thiophene (TT), (E)-2-[2-(thiophen-2yl)vinyl]thiophene (TVT) were synthesized. By replacing the sulfur atoms on benzobisthiadiazole with nitrogen atoms, benzobistriazole (BBTa) can possess alkyl chains on the central nitrogen atoms rather than on the thiophene rings along the polymer chain, which can reduce the steric hindrance between neighboring monomers and increase the planarity of polymers. The optical, thermal and electrochemical properties of the polymers were characterized, respectively. DFT calculations were used to calculate the optimized geometries of polymer backbones. The thin film microstructures of the polymers were characterized by using GIWAXS and AFM. In these novel polymers, PBTBBTa-BT displayed the highest hole mobility of 0.21 cm(2) V-1 s(-1).