學術出版;;Publications

Permanent URI for this communityhdl:11536/1

收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

Browse

🏛️國立陽明交通大學機構典藏

Search Results

Now showing 1 - 10 of 35

Conjugated Polymer/Nanocrystal Nanocomposites for Renewable Energy Applications in Photovoltaics and Photocatalysis
(2014-11-26)
Su, Yu-Wei
;
Lin, Wei-Hao
;
Hsu, Yung-Jung
;
Wei, Kung-Hwa
;
材料科學與工程學系
Conjugated polymer/nanocrystal composites have attracted much attention for use in renewable energy applications because of their versatile and synergistic optical and electronic properties. Upon absorbing photons, charge separation occurs in the nanocrystals, generating electrons and holes for photocurrent flow or reduction/oxidation (redox) reactions under proper conditions. Incorporating these nanocrystals into conjugated polymers can complement the visible light absorption range of the polymers for photovoltaics applications or allow the polymers to sensitize or immobilize the nanocrystals for photocatalysis. Here, the current developments of conjugated polymer/nanocrystal nanocomposites for bulk heterojunction-type photovoltaics incorporating Cd- and Pb-based nanocrystals or quantum dots are reviewed. The effects of manipulating the organic ligands and the concentration of the nanocrystal precursor, critical factors that affect the shape and aggregation of the nanocrystals, are also discussed. In the conclusion, the mechanisms through which conjugated polymers can sensitize semiconductor nanocrystals (TiO2, ZnO) to ensure efficient charge separation, as well as how they can support immobilized nanocrystals for use in photocatalysis, are addressed.
Synthesis and Characterization of Donor-Acceptor Poly(3-hexylthiophene) Copolymers Presenting 1,3,4-Oxadiazole Units and Their Application to Photovoltaic Cells
(2010-08-01)
Wang, Hsu-Shen
;
Su, Ming-Shin
;
Wei, Kung-Hwa
;
材料科學與工程學系
;
Department of Materials Science and Engineering
We have used Grignard metathesis polymerization to prepare poly(3-hexylthiophene)-based copolymers containing electron-withdrawing 4-tert-butylphenyl-1,3,4-oxadiazole-Phenyl moieties as side chains. We characterized these copolymers using (1)H and (13)C nuclear magnetic resonance spectroscopy, thermogravimetric analysis, and gel permeation chromatography. The band gap energy of copolymer was determined from the onset of the optical absorption. The quenching effects were observed in the photoluminescence spectra of the copolymers incorporating pendant electron-deficient 1,3,4-oxadiazole moieties on the side chains. The photocurrents of devices were enhanced in the presence of an optimal amount of the 1,3,4-oxadiazole moieties, thereby leading to improved power conversion efficiencies. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3331-3339, 2010
Synthesis and Applications of Low-Bandgap Conjugated Polymers Containing Phenothiazine Donor and Various Benzodiazole Acceptors for Polymer Solar Cells
(2010-11-01)
Padhy, Harihara
;
Huang, Jen-Hsien
;
Sahu, Duryodhan
;
Patra, Dhananjaya
;
Kekuda, Dhananjay
A series of soluble donor-acceptor conjugated polymers comprising of phenothiazine donor and various benzodiazole acceptors (i.e., benzothiadiazole, benzoselenodiazole, and benzoxadiazole) sandwiched between hexyl-thiophene linkers were designed, synthesized, and used for the fabrication of polymer solar cells (PSC). The effects of the benzodiazole acceptors on the thermal, optical, electrochemical, and photovoltaic properties of these low-bandgap (LBG) polymers were investigated. These LBG polymers possessed large molecular weight (M(n)) in the range of 3.85-5.13 x 10(4) with high thermal decomposition temperatures, which demonstrated broad absorption in the region of 300-750 nm with optical bandgaps of 1.80-1.93 eV. Both the HOMO energy level (-5.38 to -5.47 eV) and LUMO energy level (-3.47 to -3.60 eV) of the LBG polymers were within the desirable range of ideal energy level. Under 100 mW/cm(2) of AM 1.5 white-light illumination, bulk heterojunction PSC devices containing an active layer of electron donor polymers mixed with electron acceptor [6,6]-phenyl-C(61)-butyric acid methyl ester (PC(61)BM) or [6,6]-phenyl-C(71)-butyric acid methyl ester (PC(71)BM) in different weight ratios were investigated. The best performance of the PSC device was obtained by using polymer PP6DHTBT as an electron donor and PC(71)BM as an acceptor in the weight ratio of 1:4, and a power conversion efficiency value of 1.20%, an open-circuit voltage (V(oc)) value of 0.75 V, a short-circuit current (J(sc)) value of 4.60 mA/cm(2), and a fill factor (FF) value of 35.0% were achieved. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 4823-4834, 2010
Carbazole-Based Conjugated Polymers Incorporating Push/Pull Organic Dyes: Synthesis, Characterization, and Photovoltaic Applications
(2010-11-15)
Hsu, So-Lin
;
Chen, Chia-Min
;
Wei, Kung-Hwa
;
材料科學與工程學系
;
Department of Materials Science and Engineering
We have synthesized and characterized two new carbazole-based conjugated polymers, PCDCN and PCDTA, incorporating two strong light-absorbing organic dyes. These polymers exhibit relatively low band gaps (similar to 1.5 eV) and broad absorption ranges (from 300 to 700 nm). We fabricated polymer solar cells incorporating these polymers as donors and [6,6]-phenyl-C(71)-butyric acid methyl ester (PC(71)BM) as the acceptor. At a blending ratio of 1: 4, we obtained power conversion efficiencies, under simulated AM 1.5 (100 mW/cm(2)) conditions, of 2.31% and 2.47% for the PCDCN- and PCDTA-based devices, respectively. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 5126- 5134, 2010
Bond length order parameter of conjugated polymers
(1999-11-01)
Lai, CM
;
Meng, HF
;
物理研究所
;
Institute of Physics
It is usually assumed that the ground state lattice configuration of polyacetylene is a dimerized chain. We found that the energy can be further reduced by an overall chain length contraction, which leads to a new bond length order parameter, in addition to the well-known bond alternation order parameter. For quasi-particles like solitons and polarons, these two order parameters are coupled with the electron wave functions and vary in space. We generalize the Takayama-Liu-Maki equations in the continuum limit to incorporate this new order parameter. Significant modifications are found for the polaron solution. Polyacene, a ladder polymer, is also studied with the inclusion of the bond length order parameter. The ground state is predicted to be a non-alternating structure, with zero energy gap and unusually high electric conductivity. (C) 1999 Elsevier Science B.V. All rights reserved.
Deep defect levels and exciton dissociation in conjugated polymers
(2001-09-01)
Meng, HF
;
Hong, TM
;
物理研究所
;
Institute of Physics
We study the localized deep electronic level within the bandgap of conjugated polymers in the presence of structure or oxygen (carbonyl group) defects. The structure defect is modeled as a chain twist, including the chain ends as a special case. Analytic expressions for both the energy and the wavefunction of the deep levels and the itinerant levels are obtained and supplemented by clear intuitive pictures. Carbonyl group is treated numerically within the tight-binding models. The rates of free carrier capture and exciton dissociation through the defect level via multi-phonon emission are calculated. We conclude that the defect dissociation dominates the intrinsic dissociation through thermal activation, and is the primary carrier generation mechanism in photoconductivity, Our results explain the photoconductivity enhancement due to oxidation, as well as the recent observation on the temperature-independent photocurrent in the sweep-out regime. (C) 2001 Elsevier Science B.V. All rights reserved.
Synthesis and characterization of fluorescent poly [fluorene-co-phenylene-1-(di-2-pyridylamine)] copolymer and its Ru(II) complex
(2004-10-01)
Dinakaran, K
;
Chou, CH
;
Hsu, SL
;
Wei, KH
;
材料科學與工程學系
2,2'-dipyridylamine substituted poly(fluorene-co-phenylene) copolymers with different concentrations of dipyridylamine have been synthesized by Suzuki polycondensation. These polymers were found to be soluble in organic solvents such as tetrahydrofuran, chloroform, and dimethylformamide. The photoluminescence of the copolymer was slightly blueshifted as the concentration of dipridylamine was increased. The introduction of dipyridylamine and the ruthenium complex into the polymer significantly improved the photoluminescence efficiency. (C) 2004 Wiley Periodicals, Inc.
A High-Mobility Low-Bandgap Copolymer for Efficient Solar Cells
(2010-12-15)
Ding, Ping
;
Chu, Cheng-Che
;
Liu, Bo
;
Peng, Bo
;
Zou, Yingping
A new high-mobility low-bandgap polymer, PBDT-DODTBT, based on benzodithiophene and 5,6-bis(octyloxy)-4,7-di(thiophen-2-yl) benzothiadiazole has been synthesized through a standard Stille coupling reaction. The polymer is soluble in common organic solvents, such as chloroform, tetrahydrofuran, and chlorobenzene and has excellent film forming properties. Preliminary studies of the copolymer showed the charge mobility as high as 7.15 x 10(-3) cm(2).V(-1). s(-1) from SCLC measurement. Initial photovoltaic cells based on the composite structure of ITO/PEDOT: PSS/PBDT-DODTBT: (alpha)PC(71)BM (1:2)/Ca/Al showed an open-circuit voltage of 0.76 V, a power conversion efficiency of 4.02%, and a short-circuit current of 8.96mA.cm(-2).
Synthesis and Characterization of Novel Low-Bandgap Triphenylamine-Based Conjugated Polymers with Main-Chain Donors and Pendent Acceptors for Organic Photovoltaics
(2010-12-15)
Sahu, Duryodhan
;
Padhy, Harihara
;
Patra, Dhananjaya
;
Huang, Jen Hsien
;
Chu, Chih Wei
A series of novel low bandgap triphenylamine based conjugated polymers (PCAZCN PPTZCN and PDTPCN) consisting of different electron rich donor main chains (N alkyl 2 7 carbazole phenothiazine and cyclopentadithinopyrol respectively) as well as cyano and dicyano vinyl electron acceptor pendants were synthesized and developed for poly mer solar cell applications The polymers covered broad absorption spectra of 400-800 nm with narrow optical band gaps ranging 1 66-1 72 eV The highest occupied molecular or bital and lowest unoccupied molecular orbital levels of the polymers measured by cyclic voltammetry were found in the range of -5 12 to -532 V and -345 to -355 eV respectively Under 100 mW/cm(2) of AM 1 5 white light illumination bulk heterojunction photovoltaic devices composing of an active layer of electron donor polymers (PCAZCN PPTZCN and PDTPCN) blended with electron acceptor [6 6] phenyl C(61) butync acid methyl ester or [6 6] phenyl C(71) butyric acid methyl ester (PC(71)BM) in different weight ratios were investigated The photovoltaic device containing donor PCAZCN and acceptor PC(71)BM in 1 2 weight ratio showed the highest power conversion efficiency of 1 28% with V(oc) = 0 81 V J(sc) = 493 mA/cm(2) and fill factor = 32 1% (c) 2010 Wiley Periodicals Inc J Polym Sci Part A Polym Chem 48 5812-5823 2010
New Carbazole-Based Conjugated Polymers Containing Pyridylvinyl Thiophene Units for Polymer Solar Cell Applications: Morphological Stabilization Through Hydrogen Bonding
(2011-02-01)
Hsu, So-Lin
;
Chen, Chia-Min
;
Cheng, Yu-Hsin
;
Wei, Kung-Hwa
;
材料科學與工程學系
We have synthesized two conjugated polymers (P1, P2) containing alternating electron-donating and -accepting units, based on N-alkyl-2,7-carbazole, 4,7-di(thiophen-5-yl)-2,1,3-benzothiadiazole and 3-[2-(4-pyridyl)vinyl]thiophene units. These conjugated polymers contained different contents of pyridine units, which were incorporated to form hydrogen bonds with [6,6]-phenyl-C(61)-butyric acid (PCBA). When these hydrogen bonding interactions were present in the polymer thin films, their thermal stability improved; deterioration, which occurred through aggregation of PCBA methyl ester after lengthy annealing times, was also suppressed. The power conversion efficiency of a device incorporating the film featuring hydrogen bonding interactions remained at 75% of the original value after thermal annealing for 5 h at 140 degrees C. (C) 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 603-611, 2011

學術出版;;Publications

Browse

Filters

Settings

Sort By

Results per page

🏛️國立陽明交通大學機構典藏

Search Results