365547-20-2

Usage

Uses

Used in Organic Photovoltaics:
4,4-di(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b]dithiophene is used as a building block for organic semiconductors and polymers in organic photovoltaics. Its molecular structure and properties contribute to the development of high-performance solar cells with improved efficiency and stability.
Used in Organic Light-Emitting Diodes (OLEDs):
In the OLED industry, 4,4-di(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b]dithiophene is utilized as a component in the synthesis of organic materials for light-emitting diodes. Its properties enable the creation of devices with enhanced brightness, color quality, and energy efficiency.
Used in Organic Field-Effect Transistors (OFETs):
4,4-di(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b]dithiophene is employed as a key component in the development of organic field-effect transistors. Its molecular structure and properties contribute to the fabrication of high-performance transistors with improved electrical characteristics and device performance.
Used in Solution-Processable Fabrication Methods:
Due to its enhanced solubility and processability, 4,4-di(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b]dithiophene is used in solution-processable fabrication methods for electronic and optoelectronic devices. This allows for the development of devices with improved manufacturing efficiency and reduced production costs.

Upstream product

• 18908-66-2 3-bromomethylheptane 
• 389-58-2 4H-cyclopenta[2,1-b;3,4-b']dithiophene 
• 78196-93-7 (4H-cyclopenta<2,1-b:3,4-b'>dithiophene)-4-carboxylic acid 
• 7525-90-8 3-(thiophen-3-ylmethyl)thiophene 
• 474416-61-0 bis(2-iodo-3-thienyl)methanone 
• 474416-59-6 bis(2-iodothiophen-3-yl)methanol 
• 31936-92-2 1,1-di(thien-3-yl)-methanol 
• 498-62-4 3-thiophene carboxaldehyde 

Downstream Products

• 920515-35-1 2,6-bis(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-4,4-di(2-ethylhexyl)-4H-cyclopenta-[2,1-b:3,4-b']dithiophene 
• 920504-00-3 4,4-bis(2-ethylhexyl)-2,6-bis(trimethylstannyl)-4H-cyclopenta[2,1-b:3,4-b']dithiophene 
• 365547-21-3 2,6-dibromo-4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b']dithiophene 
• 1423124-61-1 4,4-bis(2-ethylhexyl)-2H-cyclopenta[2,1-b:3,4-b']dithiophene-2,6(4H)-dione 

Relevant academic research and scientific papers

In situ monitoring the thermal degradation of PCPDTBT low band gap polymers with varying alkyl side-chain patterns

The degradation pattern of a series of low band gap PCPDTBT polymers under thermal stress is investigated by in situ UV-vis and FT-IR techniques combined with thermal degradation analysis. Thermogravimetric analysis is used to predetermine the decomposition intervals, revealing that thermolysis occurs in two stages. TG-TD-GC/MS shows that loss of the alkyl side chains predominantly happens within the first temperature regime and degradation of the polymer backbone occurs thereafter. UV-vis spectroscopy is used to monitor the evolution of the optical properties upon heating, reflecting the thermal stability of the conjugated backbone, whereas FT-IR spectroscopy is applied to evaluate the chemical changes under thermal stress, with an emphasis on the polymer periphery. The influence of the side chains and possible defects, dependent on the synthesis protocol applied, on the thermal stability of the final polymers is discussed and is related to the application of said materials in organic photovoltaics.

Synthesis and characterization of cyclopentadithiophene-based low bandgap copolymers containing electron-deficient benzoselenadiazole derivatives for photovoltaic devices

We have synthesized two cyclopentadithiophene (CDT)-based low bandgap copolymers, poly[(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-b:3,4-b′] dithiophene-2,6-diyl)-alt-(benzo[c] [1,2,5]selenadiazole-4,7-diyl)] (PCBSe) and poly[(4,4-bis(2-ethylhexyl)-4H-cyclopenta[2,1-0:3,4-b′]dithiophene-2, 6-diyl)-alt-(4,7dithiophen-2-yl-benzo[c][1,2,5]selenadiazole-5,5'-diyl)] (PCT2BSe), for use in photovoltaic applications. Through the internal charge transfer interaction between the electron-donating CDT unit and the electron-accepting benzoselenadiazole, we realized exceedingly low bandgap polymers with bandgaps of 1.37-1.46 eV, The UV-vis absorption maxima of PCT2BSe were subjected to larger hypsochromic shifts than those of PCBSe, because of the distorted electron donor-acceptor (D-A) structures of the PCT2BSe backbone, These results were supported by the calculations of the D-A complex using the ab initio Hartree-Fock method with a splitvalence 6-31 G* basis set. However, PCT2BSe exhibited a better molar absorption coefficient in the visible region, which can lead to more efficient absorption of sunlight. As a result, PCT2BSe blended with [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) exhibited a better photovoltaic performance than PCBSe because of the larger spectral overlap integral with respect to the solar spectrum. Furthermore, when the polymers were blended with PC71BM, PCT2BSe showed the best performance, with an open circuit voltage of 0.55 V, a short-circuit current of 6.63 mA/cm2, and a power conversion efficiency of 1.34% under air mass 1.5 global illumination conditions.

Influence of different copolymer sequences in low band gap polymers on their performance in organic solar cells

The chemical design of a polymer can be tailored by a random or a block sequence of the comonomers in order to influence the properties of the final material. In this work, two sequences, PCPDTBT and F8BT (F8), were polymerized to form a block or a random copolymer. Differences between the various polymers were examined by exploring the surface topography and charge carrier mobility. A distinct surface texture and a higher charge carrier mobility was found for the block copolymer with respect to the other materials. Solar cells were prepared with polymer:PC71BM blend active layers and the best performance of up to 2% was found for the block copolymer, which was a direct result of the fill factor. Overall, the sequences of different copolymers for solar cell applications were varied and a positive impact on efficiency was found when the block copolymer structure was utilized.

An Unfused-Core-Based Nonfullerene Acceptor Enables High-Efficiency Organic Solar Cells with Excellent Morphological Stability at High Temperatures

Most nonfullerene acceptors developed so far for high-performance organic solar cells (OSCs) are designed in planar molecular geometry containing a fused-ring core. In this work, a new nonfullerene acceptor of DF-PCIC is synthesized with an unfused-ring core containing two cyclopentadithiophene (CPDT) moieties and one 2,5-difluorobenzene (DFB) group. A nearly planar geometry is realized through the F···H noncovalent interaction between CPDT and DFB for DF-PCIC. After proper optimizations, the OSCs with DF-PCIC as the acceptor and the polymer PBDB-T as the donor yield the best power conversion efficiency (PCE) of 10.14% with a high fill factor of 0.72. To the best of our knowledge, this efficiency is among the highest values for the OSCs with nonfullerene acceptors owning unfused-ring cores. Furthermore, no obvious morphological changes are observed for the thermally treated PBDB-T:DF-PCIC blended films, and the relevant devices can keep ≈70% of the original PCEs upon thermal treatment at 180 °C for 12 h. This tolerance of such a high temperature for so long time is rarely reported for fullerene-free OSCs, which might be due to the unique unfused-ring core of DF-PCIC. Therefore, the work provides new idea for the design of new nonfullerene acceptors applicable in commercial OSCs in the future.

Electron-deficient diketone unit engineering for non-fused ring acceptors enabling over 13% efficiency in organic solar cells

Different from the commonly studied non-fullerene electron acceptors with large fused backbone architecture and tedious synthesis steps, non-fused ring electron acceptors are attractive for organic solar cells (OSC) due to their simple synthesis and comparable device performance. However, it is key to choose appropriate building blocks for constructing non-fused ring electron acceptors to achieve high-performance OSCs. Herein, two simple non-fused ring electron acceptors,TPDC-4FandBTIC-4F, which possess the same terminals and 4H-cyclopenta[1,2-b:5,4-b′]dithiophene unit coupled with different electron-deficient diketone central units, are synthesized.TPDC-4Fwith a thieno[3,4-c]pyrrole-4,6-dione core exhibits a smaller optical bandgap of 1.42 eV, downshifted lowest unoccupied molecular orbital energy levels, higher electron mobility, and enhanced molecular packing order in neat thin films as compared toBTIC-4Fwith a 2,2′-bithiophene-3,3′-dicarboxyimide core. As a result, the OSC based onTPDC-4Fwith stronger molecular packing yielded a high power conversion efficiency (PCE) of 13.35% with aVocof 0.852 V, which is one of the best values ever reported in non-fused ring electron acceptors-based binary OSCs withVocover 0.85 V, and is better than that of OSC based on theBTIC-4Fwith weaker molecular stacking (PCE = 12.04%). This work demonstrates the application of electron-deficient diketone units in efficient non-fused ring electron acceptors and provides molecular design guidance for high-performance OSCs.

Development of low bandgap polymers for red and near-infrared fullerene-free organic photodetectors

Two photoconductive conjugated polymers (PDTPTT and PCPDTTT) were synthesized to be utilized in red and near-infrared (NIR) organic photodetectors (OPDs). The low bandgap was achieved by stabilizing the quinoidal structure of the conjugated backbone, and both donor polymers showed strong red and NIR absorption in the range of 500-900 nm. To enhance the exciton separation and intensify the red and NIR absorption, p-n bulk heterojunction OPDs were fabricated by blending a PDTPTT (or PCPDTTT) and a low bandgap nonfullerene acceptor (IDIC). The PCPDTTT:IDIC devices showed excellent OPD performances with a detectivity (D*) of 1.14 × 1012Jones and a ?3 dB bandwidth (f?3dB) of 211.7 Hz at ?1 V, whereas the PDTPTT:IDIC devices were not successful due to the high dark current density (JD) at negative bias. The interfacial energies of the PDTPTT:IDIC and PCPDTTT:IDIC blends were calculated by measuring the solvent contact angles and we found that the lower interfacial energy of the PCPDTTT:IDIC blends could make a well-mixed nanomorphology in the blend films, resulting in superior OPD properties. On the other hand, the shallow HOMO energy level (?4.66 eV) of PDTPTT could make substantialJD, which showed suboptimal OPD performances.

Planar quinone structure-containing small molecule organic semiconductor material and preparation and application thereof

The invention relates to a planar quinone structure-containing small molecule organic semiconductor material and preparation and application thereof. The general structural formula of the material isshown in a formula I. The prepared planar quinone structure-based small molecule material has good solubility, can be dissolved in common organic solvents, and organic optoelectronic devices can be prepared through processing of a solution of the small molecule organic semiconductor material; and the small molecule organic semiconductor material has good responses to solar spectra, and thus, can be used as an active layer material of organic solar cells, the migration ability of carriers can be improved due to good planarity of the small molecule organic semiconductor material, and therefore the small molecule organic semiconductor material can also be applied to preparation of active layer materials of organic field-effect transistors.

Semi-transparent low-donor content organic solar cells employing cyclopentadithiophene-based conjugated molecules

Considering the facile synthesis of the cyclopentadithiophene (CPDT) building block, this study aims to synthesize and characterize two donor-acceptor type conjugated molecules, 2EH-CPDT(FBTTh2)2 and 5EN-CPDT(FBTTh2)2, with different branching points from the backbone. It was found that the branching point variation strategy slightly tunes the optical and electrochemical properties of the resulting conjugated molecule films owing to the difference between their intermolecular packing. When used as a donor material in PC71BM-based organic solar cells (OSCs), the power conversion efficiency of 2EH-CPDT(FBTTh2)2 is twice that of the ones processed using 5EN-CPDT(FBTTh2)2. Interestingly, with no post treatments, OSCs were optimized with especially low-donor content within the active layer (donor:acceptor weight ratio = 1:9), which allows construction of a highly transparent film with a visible transmittance over 50%, showing potential for application in integrated photovoltaics.

A General Protocol for the Polycondensation of Thienyl N-Methyliminodiacetic Acid Boronate Esters to Form High Molecular Weight Copolymers

Thienyl di-N-methyliminodiacetic acid (MIDA) boronate esters are readily synthesized by electrophilic C-H borylation producing bench stable crystalline solids in good yield and excellent purity. Optimal conditions for the slow release of the boronic acid using KOH as the base in biphasic THF/water mixtures enables the thienyl MIDA boronate esters to be extremely effective homo-bifunctionalized (AA-type) monomers in Suzuki-Miyaura copolymerizations with dibromo-heteroarenes (BB-type monomers). A single polymerization protocol is applicable for the formation of five alternating thienyl copolymers that are (or are close analogues of) state of the art materials used in organic electronics. The five polymers were produced in excellent yields and with high molecular weights comparable to those produced using Stille copolymerization protocols. Therefore, thienyl di-MIDA boronate esters represent bench stable and low toxicity alternatives to highly toxic di-trimethylstannyl AA-type monomers that are currently ubiquitous in the synthesis of these important alternating copolymers.

POLYMER COMPOUND

The invention relates to a polymer compound. A photoelectric conversion device that contains the polymer compound having a structural unit represented by formula (1) has high photoelectric conversion efficiency. (wherein, X1 and X2 are the same or different and represent a nitrogen atom or -CH-. Y1 represents a sulfur atom, an oxygen atom, a selenium atom, -N(R1)- or -CR2-CR3-. R1, R2 and R3 are the same or different and represent a hydrogen atom or a substituent. W1 represents a cyano group, a monovalent organic group having a fluorine atom or a halogen atom. W2 represents a cyano group, a monovalent organic group having a fluorine atom, a halogen atom or a hydrogen atom.