Browsing by Author "Huang, Wen-Chia"

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Angular-Shaped 4,9-Dialkylnaphthodithiophene-Based Octacyclic Ladder-Type Non-Fullerene Acceptors for High Efficiency Ternary-Blend Organic Photovoltaics
(2018-08-14)
Cao, Fong-Yi
;
Huang, Wen-Chia
;
Chang, Shao-Ling
;
Cheng, Yen-Ju
;
應用化學系
An angular-shaped 4,9-didodecylnaphthodithiophene-based octacyclic ladder-type structure was developed. This new ladder-type donor (LD) was coupled with electron withdrawing IC and FIC units to form two A-LD-A type non-fullerene acceptor materials, NCIC and NCFIC. NCIC and NCFIC as the n-type acceptors are blended with a p-type donor PBDB-T to form the complementary absorption and suitable energy level alignments. The binary-blend PBDB-T:NCIC and PBDB-T:NCFIC devices achieved an efficiency of 7.3% and 7.5%, respectively. PC71BM was incorporated to form D-1:A(1):A(2) ternary blends which further strengthen the absorption at shorter wavelengths. Introduction of PC71BM not only efficiently improves the absorption but also provides multiple channels for exciton dissociation and electron transport to dramatically improve J(sc). It is interesting to find that the V-oc of the ternary-blend devices is reversely in proportional to the added amount of PC71BM. The device using the PBDB-T:NCIC:PC71BM (1:1:1 in wt %) showed an improved PCE of 8.32%. Moreover, the optimized device using the PBDB-T:NCFIC:PC71BM (1:1:1.5 in wt %) blend achieved the highest efficiency of 9.18%.
Forced coplanarity of dithienofluorene-based non-fullerene acceptors to achieve high-efficiency organic solar cells
(2019-08-14)
Cao, Fong-Yi
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Huang, Po-Kai
;
Su, Yen-Chen
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Huang, Wen-Chia
;
Chang, Shao-Ling
Ladder-type structures have been the key element for high performance non-fullerene acceptors (NFAs). In this work, two dithieno[3,2-b:6,7-b ']fluorine (DTF)-based nonfullerene acceptors, non-bridged DTFT5-FIC and carbon-bridged DTFT9-FIC, with an identical conjugated backbone were designed and synthesized for investigation of the planarization effect. The chemical rigidification with forced coplanarity indeed plays a pivotal role in determining the molecular properties. Compared to the non-bridged open-chain DTFT5-FIC counterpart, the nonacyclic ladder-type DTFT9-FIC with a fully planarized backbone exhibits higher thermal stability, bathochromic absorption and higher electron mobility. The devices using PBDB-T as the p-type polymer and fully planar DTFT9-FIC as the acceptor showed a high efficiency of 9.58%, which is superior to that of the device using the partially planar DTFT5-FIC material (5.45%). By incorporating PC71BM as the second acceptor to enhance the absorption at shorter wavelengths, optimize the morphology and facilitate electron transport, the ternary-blend device using PBDB-T:DTFT9-FIC:PC71BM achieved the highest PCE of 11.82% with a V-oc of 0.88 V, a higher J(sc) of 20.59 mA cm(-2), and an FF of 65.27%.
Highly Efficient Inverted D:A(1):A(2) Ternary Blend Organic Photovoltaics Combining a Ladder-type Non-Fullerene Acceptor and a Fullerene Acceptor
(2017-07-26)
Chang, Shao-Ling
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Cao, Fong-Yi
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Huang, Wen-Chia
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Huang, Po-Kai
;
Hsu, Chain-Shu
A formylated benzodi(cyclopentadithiophene) (BD CPDT) ladder-type structure with forced coplanarity is coupled with two 1,1-dicyanomethylene-3-indanone (IC) moieties via olefination to form a non-fullerene acceptor, BDCPDT-IC. The BDCPDT-IC, as an acceptor (A(1)) with broad light-absorbing ability and excellent solution processability, is combined with a second PC71BM acceptor (A(2)) and a medium band gap polymer, PBDB-T, as the donor (D) to form a ternary blend with gradient HOMO/LUMO energy alignments and panchromatic absorption. The device with the inverted architecture using the D:A(1):A(2) ternary blend has achieved a highest efficiency of 9.79% with a superior J(sc) of 16.84 mA cm(-2).
New Thieno[3,2-b]thiophene-Based Acceptor: Tuning Acceptor Strength of Ladder-Type N-Type Materials to Simultaneously Achieve Enhanced V-OC and J(SC) of Nonfullerene Solar Cells
(2018-07-01)
Chang, Shao-Ling
;
Cao, Fong-Yi
;
Huang, Wen-Chia
;
Huang, Po-Kai
;
Huang, Kuo-Hsiu
A new thieno[3,2-b]thiophene-incorporated acceptor TTC has been developed. The TTC acceptor was installed in a haptacyclic ladder-type core (BDCPDT) to furnish an n-type BDCPDT-TTC. The standard PBDB-T:BDCPDT-IC device showed a PCE of 9.33% with a V-OC of 0.86 V and a J(SC) of 16.56 mA/cm(2). By molecular engineering of the acceptor unit, the BDCPDT:PBDB-T-based device delivered an enhanced efficiency of 10.29% with a simultaneously enhanced V-OC of 0.94 V and J(SC) of 17.72 mA/cm(2). Incorporation of the electron-donating thieno[3,2-b]thiophene unit into the acceptor moiety decreases the electron accepting strength, thereby upshifting the HOMO/LUMO energy levels to decrease the Delta E-HOMO and E-LOSS achieving a larger Voc. Second, the extended conjugated bicyclic thieno[3,2-b]thiophene ring beneficially induces an additional optical transition at short wavelengths, leading to improvement of J. Alternatively, BDCPDT-FIC installed with the fluorinated acceptor shows more red-shifted absorption to achieve a high J of 19.12 mA/cm(2).
Synthesis and field-effect transistor properties of a diseleno[3,2-b:2 \',3 \'-d]silole-based donor-acceptor copolymer: investigation of chalcogen effect
(2016)
Pao, Yu-Chieh
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Yang, Cheng-Tai
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Lai, Yu-Ying
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Huang, Wen-Chia
;
Hsu, Chain-Shu
We have designed and synthesized a tricyclic diseleno[3,2-b:2\',3\'-d]silole (DSS) wherein the 3,3\'-position of a biselenophene is bridged by a dioctylsilyl moiety. The distannylated DSS was copolymerized with a diketopyrrolopyrrole (DPP) acceptor to form a donor-acceptor copolymer PDSSDPP. The thiophene-based dithieno[3,2-b:2\',3\'-d]silole (DTS) monomer and its corresponding copolymer PDTSDPP are also prepared as references for investigation of the chalcogen effect. Compared to PDTSDPP, PDSSDPP exhibits a more red-shifted absorption spectrum, a higher-lying HOMO energy level, and closer interchain packing associated with the more polarizable Se atom to induce stronger intermolecular interactions. The selenophene-based PDSSDPP shows a mobility of 2.47 x 10(-2) cm(2) V-1 s(-1), which is nearly one order magnitude higher than the thiophene-based PDTSDPP with a mobility of 3.89 x 10(-3) cm(2) V-1 s(-1). This result suggests that the DSS unit and its polymers are promising for OFET applications.
Synthesis and Molecular Properties of Tricyclic Biselenophene-Based Derivatives with Nitrogen, Silicon, Germanium, Vinylidene, and Ethylene Bridges
(2014-11-07)
Pao, Yu-Chieh
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Chen, Yung-Lung
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Chen, Yen-Ting
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Cheng, Sheng-Wen
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Lai, Yu-Ying
A new class of biselenophene-based materials including an sp(3)-silicon-bridged diselenosilole (DSS), an sp(3)-germanium-bridged diselenogermole (DSG), and an sp(3)-nitrogen-bridged diselenopyrrole (DSP) as well as an sp(2)-vinylidene-bridged dicyanodiselenofulvene (CDSF), a diacetylenediselenofulvene (ADSF), and a dioctylethylene-bridged benzodiselenophene (BDS) have been successfully synthesized and characterized. The bridging moieties play an important role in determining the optical and electrochemical properties. The six brominated derivatives are ready to construct various biselenophene-based conjugated materials with tunable properties for organic photovoltaics and field effect transistors.
Synthesis of unsymmetrical benzotrichalcogenophenes by N-heterocyclic carbene-palladium-catalyzed intramolecular direct C3-arylation of chalcogenophenes
(2018-02-11)
Chen, Shi-Yen
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Pao, Yu-Chieh
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Sahoo, Santosh K.
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Huang, Wen-Chia
;
Lai, Yu-Ying
A series of new unsymmetrical benzotrichalcogenophenes (BTCs) were synthesized by the Pd-N-heterocyclic carbene catalyzed intramolecular C3-arylation of furan, thiophene, selenophene and tellurophene units. This is the first time that a C3-direct arylation of selenophene and tellurophene moieties has ever been demonstrated.