- "roller-Wheel"-Type Pt-Containing Small Molecules and the Impact of "rollers" on Material Crystallinity, Electronic Properties, and Solar Cell Performance
-
We report the synthesis, characterization, and detailed comparison of a series of novel Pt-bisacetylide containing conjugated small molecules possessing an unconventional "roller-wheel" shaped structure that is distinctly different from the "dumbbell" designs in traditional Pt-bisacetylide containing conjugated polymers and small molecules. The relationships between the chemical nature and length of the "rollers" and the electronic and physical properties of the materials are carefully studied by steady-state spectroscopy, cyclic voltammetry, differential scanning calorimetry, single-crystal X-ray diffraction, transient absorption spectroscopy, theoretical calculation, and device application. It was revealed that if the roller are long enough, these molecules can "slip-stack" in the solid state, leading to high crystallinity and charge mobility. Organic solar cells were fabricated and showed power conversion efficiencies up to 5.9%, out-performing all existing Pt-containing materials. The device performance was also found to be sensitive to optimization conditions and blend morphologies, which are a result of the intricate interplay among materials crystallinity, phase separation, and the relative positions of the lowest singlet and triplet excited states.
- He, Wenhan,Livshits, Maksim Y.,Dickie, Diane A.,Zhang, Zhen,Mejiaortega, Luis E.,Rack, Jeffrey J.,Wu, Qin,Qin, Yang
-
-
Read Online
- A Facile Synthesized Polymer Featuring B-N Covalent Bond and Small Singlet-Triplet Gap for High-Performance Organic Solar Cells
-
High-efficiency organic solar cells (OSCs) largely rely on polymer donors. Herein, we report a new building block BNT and a relevant polymer PBNT-BDD featuring B-N covalent bond for application in OSCs. The BNT unit is synthesized in only 3 steps, leading to the facile synthesis of PBNT-BDD. When blended with a nonfullerene acceptor Y6-BO, PBNT-BDD afforded a power conversion efficiency (PCE) of 16.1 % in an OSC, comparable to the benzo[1,2-b:4,5-b′]dithiophene (BDT)-based counterpart. The nonradiative recombination energy loss of 0.19 eV was afforded by PBNT-BDD. PBNT-BDD also exhibited weak crystallinity and appropriate miscibility with Y6-BO, benefitting of morphological stability. The singlet–triplet gap (ΔEST) of PBNT-BDD is as low as 0.15 eV, which is much lower than those of common organic semiconductors (≥0.6 eV). As a result, the triplet state of PBNT-BDD is higher than the charge transfer (CT) state, which would suppress the recombination via triplet state effectively.
- Pang, Shuting,Wang, Zhiqiang,Yuan, Xiyue,Pan, Langheng,Deng, Wanyuan,Tang, Haoran,Wu, Hongbin,Chen, Shanshan,Duan, Chunhui,Huang, Fei,Cao, Yong
-
supporting information
p. 8813 - 8817
(2021/03/16)
-
- Effect of fluorine on optoelectronic properties in DI-A-DII-A-DI type organic molecules: A combined experimental and DFT study
-
The impact of the substitution of fluorine atom/atoms on the optoelectronic features of organic molecules having DI-A-DII-A-DI type architecture is examined in the current work. The three synthesized organic molecules (SMD1, SMD2 and SMD3) comprise of a dithienopyrrole (DTP) derivative as a central donor (DII), which is flanked between two benzothiadiazole (BT) moieties (electron acceptors, A). The BT core on each of two ends is joined to an electron-donating benzodithiophene (BDT) derivative (DI). The SMD1, SMD2 and SMD3 are substituted with 0, 2 and 4 fluorine atoms on their BT moiety respectively. The assistance of DFT methods is taken to evaluate the influence of fluorine on reorganization energies, ionizing potential and electron affinity of molecules. The thermal stability of molecules is mapped by TGA studies. Cyclic voltammetry studies are carried out to comprehend the characteristics of highest molecular orbital, lowest unoccupied molecular orbital and the bandgap of molecules, which are also supported by DFT methods. The molecules displayed better absorption properties in the near-infrared (NIR) region, excellent solution processability in a variety of organic solvents, low bandgap and optimum thermal toughness to make them applicable in the construction of OBHJSCs to play the role of donor materials when connected with acceptors like fullerene derivatives.
- Appalanaidu, Ejjurothu,Busireddy, Manohar Reddy,Chetti, Prabhakar,Vaidya, Jayathirtha Rao,Vidya, V. M.
-
-
- Regioisomeric BODIPY Benzodithiophene Dyads and Triads with Tunable Red Emission as Ratiometric Temperature and Viscosity Sensors
-
Regioisomeric acceptor-donor (AD) molecular rotors (p-AD, m-AD and m-ADA) were synthesized and characterized, wherein dyads p-AD and m-AD, and triad m-ADA contained 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) and benzodithiophene (BDT) as electron-acceptor and electron-donor, respectively. In all the compounds, the donor and acceptor moieties are electronically decoupled by a phenyl spacer, either through a para coupling or through a meta coupling. The dyad counterparts p-AD and m-AD showed distinct photophysical characteristics in which dyad p-AD showed TICT band at ca. 654 nm characterized by a Stokes shift of ca. 150 nm and prominent solvatochromism. However, meta regioisomeric triad m-ADA showed well-defined aggregation in solution. Notably, because of the temperature-tunable and solvent-viscosity-dependent emission, efficient ratiometric temperature sensing with positive and negative temperature coefficients and viscosity sensing was observed for all compounds. Interestingly, the fluorescence of dyad m-AD (in 10/90 v/v THF/water) revealed a near-white light emission with CIE chromaticity coordinates (x, y) of (0.32, 0.29). Furthermore, the fluorescence emission of p-AD in THF at 0 °C also showed a near-white light emission with chromaticity coordinates (x, y) of (0.34, 0.27). Such multifunctional rotors with readily tunable emission in the red region and prominent temperature- and viscosity-sensing abilities are promising for sensing and bioimaging applications.
- Aswathy,Sharma, Sushil,Tripathi, Narendra Pratap,Sengupta, Sanchita
-
supporting information
p. 14870 - 14880
(2019/11/13)
-
- High-efficiency synthetic method of 2,6-dibromobenzo[1,2-B:4,5-B]dithiophenol-4,8-diketone
-
The invention discloses a high-efficiency synthetic method of 2,6-dibromobenzo[1,2-B:4,5-B]dithiophenol-4,8-diketone. The high-efficiency synthetic method comprises the following steps: (1) synthesizing benzo[1,2-B:4,5-B]dithiolphenol-4,8-diketone; and (2) performing bromination reaction for the benzo[1,2-B:4,5-B]dithiolphenol-4,8-diketone. By adopting the high-efficiency synthetic method of 2,6-dibromobenzo[1,2-B:4,5-B]dithiophenol-4,8-diketone, the yield of the product 2,6-dibromobenzo[1,2-B:4,5-B]dithiophenol-4,8-diketone is greatly increased, and the requirement on the atom economy can be realized.
- -
-
Paragraph 0022; 0024; 0025; 0026; 0034; 0038; 0040; 0041-042
(2017/07/20)
-
- Dithieno[3,2-b:2′,3′-d]pyrrole-benzo[c][1,2,5]thiadiazole conjugate small molecule donors: Effect of fluorine content on their photovoltaic properties
-
Two new small molecule donors, namely ICT4 and ICT6 with D1-A-D2-A-D1 architecture having 2,4-bis(2-ethylhexyl)-4H-dithieno[3,2-b:2′,3′-d]pyrrole (EHDTP, D1) and 4,8-bis((2-ethylhexyl)oxy)benzo[1,2-b:4,5-b′]dithiophene (OBDT, D2) as the terminal and central donor, and benzo[c][1,2,5]thiadiazole (BT for ICT4) and 5,6-difluorobenzo[c][1,2,5]thiadiazole (F2BT for ICT6) as the acceptor (A) moieties, are synthesized and their optical, electronic and photovoltaic properties are investigated. Both ICT4 and ICT6 have considerable solubility in various solvents and possess efficient light absorption ability [ε (×105 mol-1 cm-1) is 0.99 and 1.06, respectively for ICT4 and ICT6] and appropriate frontier molecular orbital energy offsets with [6,6]-phenyl-C71-butyric acid methyl ester (PC71BM). Bulk heterojunction solar cells (BHJSCs) are fabricated using ICT4/ICT6 and PC71BM as donors and acceptors, respectively and BHJSCs with two-step annealed (thermal followed by solvent vapor annealing) active layers of ICT4 and ICT6 show overall power conversion efficiencies (PCEs) of 5.46% and 7.91%, respectively. The superior photovoltaic performance of the ICT6 based BHJSCs is due to the favourable morphology with a nanoscale interpenetrating network in the ICT6:PC71BM active layer induced by the fluorine atoms on the BT acceptor, which significantly enhances the dissociation of excitons, charge transport and the charge collection efficiency, and suppresses bimolecular recombination in the BHJ. The observed higher PCE of 7.91% indicates that ICT6 is one of the best BT based donor material for small molecular BHJSCs.
- Busireddy, Manohar Reddy,Chereddy, Narendra Reddy,Shanigaram, Balaiah,Kotamarthi, Bhanuprakash,Biswas, Subhayan,Sharma, Ganesh Datt,Vaidya, Jayathirtha Rao
-
p. 20513 - 20522
(2017/08/26)
-
- C10H4O2S2/graphene composite as a cathode material for sodium-ion batteries
-
Organic electroactive materials are promising candidates for next generation sodium ion batteries (SIBs) due to their low cost, sustainability and environmental benignity. It is of great interest to develop organic compounds with multifunctional groups to be used as electrode materials for SIBs owing to their light weight, multi-electron reactions, redox stability and structural diversity. The organic compound 4,8-dihydrobenzo[1,2-b:4,5-b′] dithiophene-4,8-dione (BDT) was prepared by a facile solution method, and its graphene composite (BDT-G) was synthesized by a simple dispersion-deposition process. BDT-G as a cathode material demonstrated much enhanced electrochemical performance, including higher reversible capacity (217 mA h g-1vs. 145 mA h g-1), better cycling performance (~175 mA h g-1vs. ~100 mA h g-1 after 70 cycles at 0.2C), and higher rate capabilities (1.7 times better than BDT at 2C) compared with BDT. It is revealed that these improved electrochemical properties should be mainly attributed to the excellent electronic conductivity and ionic transport efficiency promoted by graphene. Furthermore, the fast electrode reaction of BDT with the help of unlimited electron transport via the two-dimensional graphene network results in enhanced usage of materials, and BDT in the composite with graphene could be inhibited from dissolution in the organic electrolyte.
- Chen, Xiaoju,Wu, Yiwen,Huang, Zhongkang,Yang, Xiaoyun,Li, Weijie,Yu, Laura Chuan,Zeng, Ronghua,Luo, Yifan,Chou, Shu-Lei
-
p. 18409 - 18415
(2016/12/07)
-
- Dithienopyrrole-benzodithiophene based donor materials for small molecular BHJSCs: Impact of side chain and annealing treatment on their photovoltaic properties
-
Two small molecular organic materials denoted as ICT1 and ICT2 with A-D1-D2-D1-A architecture have been synthesized and their thermal, photo-physical, electrochemical and photovoltaic properties are explored. Synthesized materials have n-butylrhodanine acceptor (A), dithienopyrrole (DTP) (D1) and benzodithiophene (BDT) (D2) (Alkoxy BDT and alkylthiophene BDT, respectively for ICT1 and ICT2) donor moieties. Both the materials have good solubility (up to 25 mg/mL) in most common organic solvents and have excellent thermal stability with the decomposition temperature (Td) as 348 and 382 °C, respectively for ICT1 and ICT2. Both ICT1 and ICT2 have broad and intense visible region absorption (molar excitation coefficient is 1.71 × 105 and 1.65 × 105 mol?1 cm?1, respectively for ICT1 and ICT2) and have suitable HOMO and LUMO energy levels for PC71BM acceptor. Bulk heterojunction solar cells with ITO/PEDOT:PSS/blend/Al structure are fabricated using these materials. The BHJSCs fabricated by spin cast of ICT1:PC71BM and ICT2:PC71BM (1:2 wt ratio) blend from chloroform showed power conversion efficiency (PCE) of 2.77% (Jsc = 6.84 mA/cm2, Voc = 0.92 V and FF = 0.44) and 3.27% (Jsc = 7.26 mA/cm2, Voc = 0.96 V and FF = 0.47), respectively. Annealing the active layer significantly improved the PCE of these BHJSCs to 5.12% (Jsc = 10.15 mA/cm2, Voc = 0.87 V and FF = 0.58) and 5.90% (Jsc = 10.68 mA/cm2, Voc = 0.92 V and FF = 0.60), respectively for ICT1 and ICT2 donors. The enhancement in the PCE is due to higher light harvesting ability of the active layer, better nanoscale morphology for efficient and balanced charge transport and effective exciton dissociation at the donor-acceptor interface.
- Busireddy, Manohar Reddy,Mantena, Venkata Niladri Raju,Chereddy, Narendra Reddy,Shanigaram, Balaiah,Kotamarthi, Bhanuprakash,Biswas, Subhayan,Sharma, Ganesh Datt,Vaidya, Jayathirtha Rao
-
p. 312 - 325
(2016/07/21)
-
- A highly selective and sensitive probe based on benzo[1,2-b:4,5-b′]dithiophene: Synthesis, detection for Cu(II) and self-assembly
-
A novel turn-off probe for copper(II) containing benzo[1,2-b:4,5-b′]dithiophene (BDT) and two picolinamide units was synthesized. In this probe, two picolinamide units complex with one Cu2+ ion and two nitrogen atoms in each picolinamide unit coordinate with Cu2+, which is verified by DFT calculation. Its fluorescence quantum yield is 0.43 and the detection limit is as low as 2.4×10-8 mol/L. The results show that the probe displays good selectivity for Cu2+ over other ions (Mn2+, Pb2+, Cr3+, Zn2+, Ni2+, K+, Ca2+, Ag+, Mg2+, Fe3+, Fe2+, Hg2+, Al3+, Cd2+, Pd2+, Co2+). Furthermore, the probe induced by Cu2+ and the π-π interaction of the aromatic unit can also form rod structure assembly, which can be observed by scanning electron microscopy (SEM).
- Ma, Yuwen,Leng, Taohua,Lai, Guoqiao,Li, Zhifang,Xu, Xiaojia,Zou, Jianwei,Shen, Yongjia,Wang, Chengyun
-
p. 2219 - 2225
(2016/04/09)
-
- A Benzodithiophene-Based Fluorescence Probe for Rapid Detection of Fluoride Ion
-
A novel and simple fluorescence probe was synthesized from benzo[1,2-b:4,5-b′]dithiophene (BDT) and trimethylsilylethyne via Sonogashira reaction, and showed highly selective and sensitive fluorescence decreasing response towards F?. The probe molecule turned to a weakly fluorescent terminal alkyne moiety because its trimethylsilyl (TMS) group was cleaved by fluoride, which was proved by1H NMR titration. Whereas no distinct fluorescent changes were observed with the addition of other anions, such as Cl?, Br?, I?, AcO?and H2PO4?. Upon the addition of F?, the maximum fluorescence emission wavelength shifted from 460 nm to 450 nm with a decrease of fluorescence intensity by 40% within 20 s. Moreover, the detection limit towards F?was calculated to be as low as 73.5 nmol/L.
- Tan, Wenbin,Leng, Taohua,Lai, Guoqiao,Li, Zhifang,Wu, Jiefei,Shen, Yongjia,Wang, Chengyun
-
supporting information
p. 809 - 813
(2016/08/31)
-
- A "roller-wheel" Pt-containing small molecule that outperforms its polymer analogs in organic solar cells
-
A novel Pt-bisacetylide small molecule (Pt-SM) featuring "roller-wheel" geometry was synthesized and characterized. When compared with conventional Pt-containing polymers and small molecules having "dumbbell" shaped structures, Pt-SM displays enhanced crystallinity and intermolecular π-π interactions, as well as favorable panchromatic absorption behaviors. Organic solar cells (OSCs) employing Pt-SM achieve power conversion efficiencies (PCEs) up to 5.9%, the highest reported so far for Pt-containing polymers and small molecules.
- He, Wenhan,Livshits, Maksim Y.,Dickie, Diane A.,Yang, Jianzhong,Quinnett, Rachel,Rack, Jeffrey J.,Wu, Qin,Qin, Yang
-
p. 5798 - 5804
(2016/09/03)
-
- 2,6-bis(triphenylamine)-4,8-bis(alkoxy)benzo[1,2-b:4,5-b']bithiophene and preparation for same
-
The invention discloses a hole transport material 2,6-bis(triphenylamine)-4,8-bis(alkoxy)benzo[1,2-b:4,5-b']bithiophene for a perovskite solar cell. The hole transport material has a simple molecular structure, a lateral group to which an aromatic functional group can be introduced, high hole mobility, high efficiency, high electrical conductivity and high dissolubility, and the perovskite solar cell prepared from the hole transport material can be matched with a perovskite energy level. The invention also discloses a preparation method for the hole transport material. The hole transport material for the perovskite solar cell is prepared by an SUZUKI reaction step from raw materials 2,6-dibromo-4,8-bis(alkoxy)benzo[1,2-b:4,5-b']dithiophene and 4-(diphenylamino)phenylboronicacid. The preparation method has the characteristics of simplicity in operation, readily available raw materials, easiness for separation and high yield.
- -
-
Paragraph 0015; 0016
(2017/07/21)
-
- Correlation of structure and photovoltaic performance of benzo[1,2-b:4,5-b′]dithiophene copolymers alternating with different acceptors
-
Four π-conjugated benzo[1,2-b:4,5-b′]dithiophene (BDT) based polymers were synthesized for application in polymer solar cells. These polymers possessed desirable HOMO/LUMO levels for polymer photovoltaic applications. PBDTT-TTz and PBDTT-DTBT displayed strong absorption in the range of 300-650 nm, while PBDTT-DPP and PBDTT-TTDPP showed a further 100 nm extended absorption band. The lowest unoccupied molecular orbital energy levels of polymers were tuned effectively from -3.34 eV to -3.81 eV by fusing with different accepting units. A maximum power conversion efficiency of 2.60% was obtained from photovoltaic cells with a PBDTT-TTz:PC61BM (1:2, w/w) blend film as the active layer, with a short circuit current density of 8.37 mA cm-2, an open circuit voltage of 0.70 V, and a fill factor of 44.3%. This journal is
- Yu, Jiangsheng,Zhao, Baofeng,Nie, Xuemei,Zhou, Baojin,Li, Yang,Hai, Jiefeng,Zhu, Enwei,Bian, Linyi,Wu, Hongbin,Tang, Weihua
-
supporting information
p. 2248 - 2255
(2015/03/18)
-
- Synthesis of Amphiphilic RuII Heteroleptic Complexes Based on Benzo[1,2-b:4,5-b′]dithiophene: Relevance of the Half-Sandwich Complex Intermediate and Solvent Compatibility
-
The detailed synthesis and characterization of four ruthenium(II) complexes [RuLL′(NCS)2] is reported, in which L represents a 2,2′-bipyridine ligand functionalized at the 4,4′ positions with benzo[1,2-b:4,5-b′]dithiophene derivatives (BDT) and L′ is 2,2′-bipyridine-4,4′-dicarboxylic acid unit (dcbpy) (NCS=isothiocyanate). The reaction conditions were adapted and optimized for the preparation of these amphiphilic complexes with a strong lipophilic character. The photovoltaic performances of these complexes were tested in TiO2 dye-sensitized solar cell (DSSC) achieving efficiencies in the range of 3-4.5 % under simulated one sun illumination (AM1.5G).
- Urbani, Maxence,Medel, María,Kumar, Sangeeta Amit,Ince, Mine,Bhaskarwar, Ashok N.,González-Rodríguez, David,Gr?tzel, Michael,Nazeeruddin, Mohammad Khaja,Torres, Tomás
-
supporting information
p. 16252 - 16265
(2015/11/03)
-
- organic semiconductor compound, manufacturing method thereof, and organic electronic device that contains it
-
The present invention relates to an organic semiconductor compound, a method for manufacturing the same, and an organic electronic device comprising the same and, more specifically, to an organic semiconductor compound including quinoxaline, a method for manufacturing the same, and an organic electronic device comprising the same. In addition, by having a low band gap by synthesizing and copolymerizing a thiophene derivative containing sulfur (S) with a quinoxaline-based compound, the organic electronic device comprising the same has a higher efficiency with an innovative combination with a fullerene derivative, which is a photoactive layer, with the organic semiconductor compound of the present invention. The organic semiconductor compound of the present invention has high thermal stability and high solubility and the organic electronic device comprising the same has excellent electric characteristics, thereby can be valuably used as a n-type material of the organic electronic device, especially an organic solar cell or an organic thin film transistor.
- -
-
Paragraph 0184; 0191-0192
(2016/10/09)
-
- Investigation of benzo(1,2-b:4,5-b′)dithiophene as a spacer in organic dyes for high efficient dye-sensitized solar cell
-
Two benzo(1,2-b:4,5-b′)dithiophene (denoted as BDT) based organic dyes, Dye 1 and Dye 2, containing triphenylamine and carbazole in the molecular frameworks respectively, were synthesized, characterized and applied in dye-sensitized solar cells (DSSCs). The photo-physical, photovoltaic, and electrochemical properties of the two dyes were analyzed in this work. The two dyes exhibit strong charge transfer absorption bands in the visible region. The dyes were applied in dye sensitized solar cells obtaining 11.34 mA/cm2, 0.75 V and 0.74, for the short-circuit photocurrent density (Jsc), open-circuit voltage (Voc), and fill factor (FF) respectively, corresponding to an overall power conversion efficiency of 6.3%. These results revealed that BDT-based dyes are promising dyes for DSSCs.
- Zhou, Xiaole,Li, Xianghong,Liu, Yuwen,Li, Renjie,Jiang, Kejian,Xia, Jiangbin
-
p. 245 - 253
(2015/07/15)
-
- Evaporable organic semiconductive material and use thereof in an optoelectronic component
-
The invention relates to compounds of general formula IIIa and their use in optoelectronic components.
- -
-
Page/Page column 48
(2015/10/05)
-
- CONJUGATED POLYMERS FOR ELECTRONIC DEVICES
-
A conjugated polymer for electronic devices can include a repeated unit having the structure of formula (I)
- -
-
Page/Page column
(2015/02/19)
-
- Direct access to 4,8-functionalized benzo[1,2-b:4,5-b′]dithiophenes with deep low-lying HOMO levels and high mobilities
-
A general methodology has been proposed for the straightforward access to 4,8-functionalized benzo[1,2-b:4,5-b′]dithiophenes (BDTs) via Pd mediated coupling reactions including Suzuki-Sonogashira coupling and carbon-sulfur bond formation reactions. This versatile platform can be used to construct a library of BDT core centred conjugated systems, featuring large fused-ring structure and good charge mobility, where a hole mobility of 0.061 cm2 V -1 s-1 is demonstrated. With the energy level fine-tuned with functionalization, the charge transporting BDTs show great potential for donor-acceptor polymers. This journal is the Partner Organisations 2014.
- Zhu, Enwei,Ge, Guidong,Shu, Jingkun,Yi, Mingdong,Bian, Linyi,Hai, Jiefeng,Yu, Jiangsheng,Liu, Yun,Zhou, Jie,Tang, Weihua
-
supporting information
p. 13580 - 13586
(2014/08/18)
-
- Benzo[1,2-b:4,5-b′]dithiophene and benzo[1,2-b:4,5-b′]difuran based organic dipolar compounds for sensitized solar cells
-
Novel organic dyes that consist of either a benzo[1,2-b:4,5-b′] dithiophene or a benzo[1,2-b:4,5-b′]difuran core exhibited remarkable solar-to-energy conversion efficiency in dye-sensitized solar cells. The planar geometry of bridge moiety and its bulky substituents helped the dyes to form a high quality monolayer on the surface of titanium oxide. A typical device displayed photon-to-current conversion efficiency 60% in the region of 380-575 nm, a short-circuit photocurrent density 13.45 mA cm-2, an open-circuit photovoltage 0.72 V, and a fill factor 0.63, corresponding to an overall conversion efficiency 6.12%. In a test of using deoxycholic acid as a co-absorbent, an improvement of quantum efficiencies 8.37% was observed for certain compounds. However, for others the quantum efficiency decreased in 6.60-7.91%. The latter result indicated that the quality of some films cannot be further improved by the addition of deoxycholic acid. The photophysical properties were analyzed with the aid of TDDFT.
- Lin, Yan-Zuo,Yeh, Chia-Wei,Chou, Po-Ting,Watanabe, Motonori,Chang, Yu-Hsuan,Chang, Yuan Jay,Chow, Tahsin J.
-
-
- New low band gap 2-(4-(trifluoromethyl)phenyl)-1H-benzo[d]imidazole and benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole based conjugated polymers for organic photovoltaics
-
Two new low band gap D-A structured conjugated polymers, PBDTTBI and PBDTBBT, based on 2-(4-(trifluoromethyl)phenyl)-1H-benzo[d]imidazole and benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole acceptor units with benzo[1,2-b;3,4-b′]dithiophene as a donor unit have been designed and synthesized via a Stille coupling reaction. The incorporation of the benzo[1,2-c;4,5-c′]bis[1,2,5]thiadiazole unit into PBDTBBT has significantly altered the optical and electrochemical properties of the polymer. The optical band gap estimated from the onset absorption edge is ~1.88 eV and ~1.1 eV, respectively for PBDTTBI and PBDTBBT. It is observed that PBDTBBT exhibited a deeper HOMO energy level (-4.06 eV) with strong intramolecular charge transfer interactions. Bulk heterojunction solar cells fabricated with a configuration of ITO/PEDOT:PSS/PBDTBBT:PC71BM/Al exhibited a best power conversion efficiency of 0.67%, with a short circuit current density of 4.9 mA cm-2, an open-circuit voltage of 0.54 V and a fill factor of 25%.
- Murali,Rao, Arun D.,Ramamurthy, Praveen C.
-
p. 44902 - 44910
(2014/12/11)
-
- Benzodithiophene and imide-based copolymers for photovoltaic applications
-
Conjugated alternating copolymers were designed with low optical band gaps for organic photovoltaic (OPV) applications by considering quinoid resonance stabilization. Copolymers of thienoisoindoledione (TID) and benzodithiophene (BDT) had appreciably lower band gaps (by ~0.4 eV) than copolymers of thienopyrroledione (TPD) and BDT. In addition to intramolecular charge transfer stabilization (i.e., the "push-pull" effect), the former copolymer's quinoid resonance structure is stabilized by a gain in aromatic resonance energy in the isoindole unit. Additionally, the HOMO levels of the copolymers could be tuned with chemical modifications to the BDT monomer, resulting in open circuit voltages of greater than 1 V in photovoltaic devices. Despite the optimized band gap, TID containing polymers displayed lower photoconductance, as determined by time-resolved microwave conductivity, and decreased device efficiency (2.1% vs 4.8%) as compared with TPD analogues. These results were partially attributed to morphology, as computational modeling suggests TID copolymers have a twisted backbone, and X-ray diffraction data indicate the polymer films do not form ordered domains, whereas TPD copolymers are considerably more planar and are shown to form partially ordered domains.
- Braunecker, Wade A.,Owczarczyk, Zbyslaw R.,Garcia, Andres,Kopidakis, Nikos,Larsen, Ross E.,Hammond, Scott R.,Ginley, David S.,Olson, Dana C.
-
experimental part
p. 1346 - 1356
(2012/08/28)
-
- Incorporation of pyrene units to improve hole mobility in conjugated polymers for organic solar cells
-
Solution-processable semiconducting copolymers, poly[N-9′- heptadecanyl-2,7-carbazole-alt-5,5′-(4′,7′-di-2-thienyl- 2′,1′,3′-benzothiadiazole)] (PCDTBT) and poly[4,8-bis(2- ethylhexyl-2-thenyl)-benzo[1,2-b:4,5-b′]dithiophene-alt-5, 5′-(4′,7′-di-2-thienyl-2′,1′,3′- benzothiadiazole)] (PBDTDTBT), and their pyrene-containing terpolymers were synthesized using Suzuki or Stille coupling. Pyrene units were introduced to improve the charge-transporting abilities of the polymers. The resulting polymers were found to be soluble in common organic solvents and formed smooth and uniform spin-coated thin films. They also exhibited good thermal stability and lost 71BM/Ca/Al configuration fabricated using the pyrene-containing polymers had higher power conversion efficiencies than those using the corresponding parent polymers.
- Kim, Ji-Hoon,Kim, Hee Un,Kang, In-Nam,Lee, Sang Kyu,Moon, Sang-Jin,Shin, Won Suk,Hwang, Do-Hoon
-
p. 8628 - 8638
(2013/01/15)
-
- Fluoroalkyl Thieno- and Benzo-fused γ-Lactones
-
The four aryl-fused perfluoroalkyl γ-lactones 6-9 have been prepared by the directed ortho-lithiation of the N,N-diethylamide 10 and the oxazolines 15 and 20 followed by reaction with either pentafluoroacetone or hexafluoroacetone.The two thiophene lactones 6 and 7 gave their corresponding hydroxy acids 18 and 14, while the benzene lactone 8 lost the elements of CF2 on saponification to give a new γ-lactone 24 and its corresponding hydroxy acid 25.This acid closed spontaneously to 24 as did, even more rapidly, the hydroxy acid 28 of lactone 9.
- Reinecke, Manfred G.,Chen, Lao-Jer
-
p. 318 - 322
(2007/10/02)
-
- Synthesis of Benzodithiophene and its 4,8-Dimethoxy and 4,8-Dimethyl Derivatives
-
Eine einfache Synthese fuer Benzodithiophen (4) und die Synthese seines bisher unbekannten 4,8-Dimethoxy- (7) and 4,8-Dimethylderivates (13) wird beschrieben.IR-, 1H NMR-, UV- und MS-Daten werden mitgeteilt.
- Beimling, Peter,Kossmehl, Gerhard
-
p. 3198 - 3203
(2007/10/02)
-
- 9,10-Bis(aminoalkoxy)anthracenes
-
This disclosure describes certain substituted 9,10-bis(2-aminoethoxy)anthracenes which are useful as modulators of the immune response system in warm-blooded animals and for inducing the regression of tumors in such animals.
- -
-
-
- Thermolysis of Thiophenedicarboxylic Acid Anhydrides as a Route to Five-Membered Hetarynes
-
Flow vacuum thermolysis (FVT) of the anhydrides of thiophene-2,3- (5) and -3,4-dicarboxylic acid (6) and of thianaphthene-2,3-dicarboxylic acid (7) in the presence of thiophene, 1,3-cyclohexadiene, or benzene gave thianthrene (15a), presumably by aromatization of an intermadiate Diels-Alder adduct of the diene traps and the aryne 2,3-didehydrothiophene (8).A similar rationale explains the formation of dibenzothiophene from 7 and thiophene, the four monomethylthianaphthenes 22-25 from 5 and cyclopentadiene, 5,6-dimethylthianaphthene (15f) from 5 and 2,3-dimethylbutadiene, and a mixture of hydroxythianaphthenes (15d) from 5 and furan.The latter reaction also produces a mixture of isomeric cyclopentanothiophenes (19) which probably arise by decarbonylation of 15d.An FVT reaction of 5 with propyne as the trap gave a mixture of allenyl-(28) and propynylthiophenes 29 which probably arise by an ene reaction of the trap and the aryne 8.Decomposition of the anhydrides 5 and 6 in molten anthracene led only to Friedel-Crafts products such as thienylanthracenes 33 and quinones 34 from 5 and 39 and 40 from 6.The diene reactivity of thiophene 13a in the gas phase was demonstrated by the formation of naphthalene from its reaction with benzyne generated from the thermolysis of indanetrione and by the formation of indene from 13a plus cyclopentadiene.Possible, but improbable, interpretations of the FVT results without invoking a five-membered hetaryne intermediate are considered.
- Reinecke, Manfred G.,Newsom, James G.,Chen, Lao-Jer
-
p. 2760 - 2769
(2007/10/02)
-