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Serife O. Hacioglu Emre Ataoglu Gonul Hizalan Tolga Depci Levent Toppare 《Phosphorus, sulfur, and silicon and the related elements》2013,188(9):937-946
AbstractTwo novel thiadiazoloquinoxaline and benzodithiophene (BDT) bearing copolymers were designed and synthesized. Different BDT units (alkoxy and thiophene substituted) were used as donor materials and the effect of alkoxy and thiophene substitution on the electrochemical, spectroelectrochemical and photovoltaic properties were investigated. Both polymers exhibited low oxidation potentials at around 0.90 V and low optical band gaps at around 1.00?eV due to the insertion of electron poor thiadiazoloquinoxaline unit into the polymer backbone. Both P1 (poly-6,7-bis(3,4-bis(decyloxy)phenyl)-4-(4,8-bis(nonan-3-yloxy)benzo[1,2-b:4,5-b']dithiophen-2-yl)-[1, 2, 5]thiadiazolo[3,4-g]quinoxaline) and P2 (poly- 4-(4,8-bis(5-(nonan-3-yl)thiophen-2-yl)benzo[1,2-b:4,5-b']dithiophen-2-yl)-6,7-bis(3,4-bis(decyloxy)phenyl)-[1, 2, 5]thiadiazolo[3,4-g]quinoxaline) exhibited multichromic behavior with different tones of greenish yellow and gray in the neutral and fully oxidized states, respectively. In addition, both polymers revealed very high optical contrasts (~87%) in the NIR region which make these promising polymers good candidates for NIR applications. Finally, in order to explore the organic photovoltaic performances, P1 and P2 were mixed with PC71BM in the active layer of organic solar cells (OSCs) by conventional device structure. As a result P1 and P2 based devices revealed power conversion efficiencies (PCEs) of 0.33% and 0.60% respectively. However, the additive treatment enhanced PCE from 0.49 to 0.73% for P2 based devices. 相似文献
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We have achieved, for the first time to our knowledge, lasing in a new type of telluride-tungstate glass host doped with neodymium: Nd3+:(0.8)TeO2-(0.2)WO3. Lasing was obtained at 1065 nm with two samples containing 0.5 mol% and 1.0 mol% Nd2O3. During gain-switched operation, slope efficiencies of 12% and 10% were obtained with the 0.5 mol% and 1.0 mol% doped samples, respectively, at a pulse repetition rate of 1 kHz. Judd-Ofelt analysis was further employed to determine the emission cross section σe at 1065 nm from the absorption spectra and lifetime data. The emission cross section from the Judd-Ofelt analysis came to 3.23 ± 0.09 × 10−20 cm2, in reasonable agreement with the value of 2.0 ± 0.13 × 10−20 cm2 obtained from the analysis of laser threshold data. 相似文献
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Incorporation of different conjugated linkers into low band gap polymers based on 5,6‐Bis(octyloxy)‐2,1,3 benzooxadiazole for tuning optoelectronic properties
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Seza Goker Gonul Hizalan Seda Kutkan Yasemin Arslan Udum Ali Cirpan Levent Toppare 《Journal of polymer science. Part A, Polymer chemistry》2016,54(16):2459-2467
Four new 2,1,3‐benzooxadiazole‐based donor–acceptor conjugated polymers, namely poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSC), poly{9‐(9‐heptadecanyl)‐9H‐carbazole‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFC), poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(selenophen‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PSBSFL), and poly{9,9‐dioctyl‐9H‐fluorene‐alt‐5,6‐bis(octyloxy)‐4,7‐di(furan‐2‐yl)benzo[c][1,2,5]oxadiazole)}(PFBFFL), were synthesized via Stille polycondensation reaction. All polymers were found to be soluble in common organic solvents such as chloroform, tetrahydrofuran, and chlorobenzene. Their structures were verified by 1H‐NMR and the molecular weights were determined by gel permeation chromatography (GPC). The polymer films exhibited broad absorption bands. Among all polymers, photovoltaic cells based on the device structure of ITO/PEDOT:PSS/PSBSC:PC71BM(1:3, w/w)/LiF/Al revealed an open‐circuit voltage of 0.62 V, a short circuit current of 7.63 mA cm?2 and a power conversion efficiency of 1.89%. This work demonstrates a good example for tuning absorption range, energy level, and photovoltaic properties of the polymers with different spacers and donor units can offer a simple and effective method to improve the efficiency of PSCs. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2459–2467 相似文献
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A theoretical investigation of the band alignment of type-I direct band gap dilute nitride phosphide alloy of GaN_xAs_yP_(1-x-y)/GaP quantum wells on GaP substrates
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The GaP-based dilute nitride direct band gap material Ga(NAsP) is gaining importance due to the monolithic integra- tion of laser diodes on Si microprocessors. The major advantage of this newly proposed laser material system is the small lattice mismatch between GaP and Si. However, the large threshold current density of these promising laser diodes on Si substrates shows that the carrier leakage plays an important role in Ga(NAsP)/GaP QW lasers. Therefore, it is necessary to investigate the band alignment in this laser material system. In this paper, we present a theoretical investigation to optimize the band alignment of type-I direct band gap GaNxAsyP1-x-y/GaP QWs on GaP substrates. We examine the effect of nitrogen (N) concentration on the band offset ratios and band offset energies. We also provide a comparison of the band alignment of type-I direct band gap GaNxAsyP1-x-y/GaP QWs with that of the GaNxAsyP1-x-y/Al2Ga1-2P QWs on GaP substrates. Our theoretical calculations indicate that the incorporations of N into the well and AI into the barrier improve the band alignment compared to that of the GaAsP/GaP QW laser heterostructures. 相似文献
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Elif Ozcelik Kazancioglu Gonul S. Batibay Ahmet Uner Nergis Arsu 《Journal of polymer science. Part A, Polymer chemistry》2021,59(8):729-737
In this study, hybrid nanocomposites were synthesized by photo-crosslinking of poly (ethylene glycol) methyl ether acrylate/poly (ethylene glycol) diacrylate monomer system using 2- (carboxymethoxy) thioxanthone and POSS-(PEG2000)8. Additionally, AgNO3 was added to this formulation and in situ formation of silver nanoparticles onto hybrid nanocomposites were achieved in one-step. UV–Vis spectroscopy technique was used as a very useful tool for surface plasmon resonance band detection of silver nanoparticles. In addition to thermogravimetric analyses which were performed in nitrogen atmosphere to determine the thermal stability of the nanocomposites, dynamic light scattering, and scanning electron microscopy techniques were also used for size and morphology of silver nanoparticles in a hybrid network. TGA analyses proved that even the addition of a very low amount of POSS-(PEG2000)8 made noteworthy contribution to thermal stability especially in the presence of silver nanoparticles in the hybrid network. The swelling capacities of the prepared films were examined at 1, 3 and 24 h in phosphate buffer solution (pH = 7.4). It was found that film containing only POSS-(PEG2000)8 had the highest swelling ratio in the shortest time. 相似文献
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In this study, two new conjugated polymers were synthesized including benzotriazole (BTz) as the acceptor unit and selenophene as the π bridge donor segment. These acceptors were coupled with fluorene and carbazole via Suzuki condensation reactions. Electrochemical band gaps were calculated as 2.45 eV for P1 and 2.40 eV for P2. Electrochemical and optical studies of polymers indicate that both polymers are promising candidates for organic solar cell (OSC) and polymer organic light emitting diode (PLED) applications since they have suitable HOMO-LUMO energy levels and appropriate absorption and emission band ranges. Light emitting properties of synthesized polymers were investigated and the highest luminance value was found as 6608cd/m2 for P1 at 8 V. Photovoltaic properties of polymers were investigated and the optimized device based on P2 showed 1.75% power conversion efficiency for P2 under AM 1.5 G illumination at 100 mW/cm2. 相似文献
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Ozan Erlik Naime A. Unlu Gonul Hizalan Serife O. Hacioglu Seda Comez Esra D. Yildiz Levent Toppare Ali Cirpan 《Journal of polymer science. Part A, Polymer chemistry》2015,53(13):1541-1547
In this study, four novel silafluorene (SiF) and benzotriazole (Btz) bearing conjugated polymers are synthesized. In the context of electrochemical and optical studies, these polymers are promising materials both for electrochromic device (ECD) and polymer solar cell (PSC) applications. All of the polymers are ambipolar (both p‐ and n‐dopable) and multichromic. Electrochemistry experiments indicate that incorporation of selenophene instead of thiophene unit increases the HOMO energy level of the polymers. Power conversion efficiency of the PSCs reached 1.75% for PTBTSiF, 1.55% for PSBSSiF, 2.57% for PBTBTSiF, and 1.82% for PBSBSSiF. The hole mobilities of the polymers are estimated through space charge limited current (SCLC) model. PBTBTSiF has the highest hole mobility as 2.44 × 10?3 cm2 V s?1. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1541–1547 相似文献
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Benzotriazole and benzodithiophene containing medium band gap polymer for bulk heterojunction polymer solar cell applications
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Hande Unay Naime A. Unlu Gonul Hizalan Serife O. Hacioglu Dilber Esra Yildiz Levent Toppare Ali Cirpan 《Journal of polymer science. Part A, Polymer chemistry》2015,53(4):528-535
An alternating donor‐acceptor copolymer based on a benzotriazole and benzodithiophene was synthesized and selenophene was incorporated as π‐bridge. The photovoltaic and optical properties of polymer were studied. The copolymer showed medium band gap and dual absorption peaks in UV‐Vis absorption spectra. Photovoltaic properties of P‐SBTBDT were performed by conventional device structure. The OSC device based on polymer: PC71BM (1:1, w/w) exhibited the best PCE of 3.60% with a Voc of 0.67 V, a Jsc of 8.95 mA/cm2, and a FF of 60%. This finding was supported with morphological data and space charge limited current (SCLC) mobilities. The hole mobility of the copolymer was estimated through SCLC model. Although surface roughness of the active layer is really high, mobility of a polymer was found as 7.46 × 10?3 cm2/Vs for optimized device that can be attributed to Se?Se interactions due to the larger, more‐polarizable Se atom. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 528–535 相似文献