• Bulletin of the Korean Chemical Society
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• v.28 no.7
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• pp.1175-1182
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• 2007

A series of new organic semiconductors hexyl end-capped thiophene-anthracene oligomers containing the anthracene moiety in the center of the oligomers are synthesized. The target oligomers have been obtained by Stille coupling reactions as key step reactions. The synthesized thiophene-anthracene oligomers were characterized by 1H-NMR, 13C-NMR and high-resolution mass spectroscopy, respectively. All of the oligomers are soluble in chlorinated solvents. Their optical, thermal and electrochemical properties were measured. The hexyl end-capped oligomers and their unsubstituted oligomers exhibit the same absorption behavior in dilute toluene solution. Hexyl end-capped bis-terthienylanthracene oligomer is observed to show liquid crystalline mesophase at 166 oC in heating process. The thermal analyses as well as the electrochemical measurement data indicate that the designed materials show better thermal and oxidation stability than the corresponding oligothiophenes without anthracene core. Fluorescence lifetimes and fluorescence quantum yields of the thiophene-anthracene oligomers are measured to be 10-14 ps and 3.4-9.9 × 10?3 which are much shorter and lower than those of oligothiophenes respectively.

• Applied Chemistry for Engineering
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• v.33 no.3
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• pp.289-295
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• 2022

In this study, we intend to fabricate an all solid polymer battery with a reduced interfacial resistance between the solid electrolyte and the electrode by applying thiophene based polymers as both electrode and electrolyte materials. In order to minimize the interfacial resistance with the poly(3,4-ethylenedioxy thiophene) (PEDOT) based electrode, 3,4-ethylenedioxy thiophene (EDOT) oligomer was introduced into the solid electrolyte. Also, to improve the lithium salt dissociation ability of the EDOT oligomer [oligo(EDOT)] electrolyte, it was blended with poly(vinylidene fluoride) (PVdF). As a result, the ionic conductivity of the solid polymer electrolyte increased by introducing PVdF into the oligo (EDOT). From the result of evaluating the electrochemical properties of an all solid polymer battery, the interfacial resistance significantly decreased by introducing a thiophene based polymer to the electrode and electrolyte.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.518-520
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• 1997

Recently, thiophene oligomer with short chain lengths has received much attention as model compounds for facilitating better understanding of electronic and optical properties of polymers, because oligomer is well-defined chemical systems and its conjugation chain length can be exactly controlled. Moreover, organic this films based on conjugated thiophene oligomer have potential for application to electronic and optoelectronic devices such as MISFETs(metal-insulator-semiconductor field-effect transistors) and LEDs(light-emitting diodes). However, there is little knowledge on electronic and structural properties of linear-conjugated oligothiophenes in solid states, compared with those in solutions. $\alpha$-sexithienyl($\alpha$-6T) thin-films were deposited by OMBD(Organic Molecular Beam Deposition) technique, where the $\alpha$-6T was synthesized and purified by the sublimation method. The $\alpha$-6T films were deposited under various conditions. The effects of deposition rate, substrate temperature, and vacuum pressure on the formation of these films have been studied. The molecules in the $\alpha$-6T film deposited at a low deposition rate under a high vacuum were aligned almost perpendicular to the substrate. The $\alpha$-6T films deposited at an elevated substrate temperature showed higher conductivity than the film deposited at room temperature. Electrical characterization of these films will be also executed by using four-point probe measurement technique.

• Bulletin of the Korean Chemical Society
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• v.23 no.3
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• pp.518-520
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• 2002

• Korean Chemical Engineering Research
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• v.49 no.1
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• pp.95-100
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• 2011

During the development of low band-gap organic materials(p-type semiconducting organic compounds) for organic solar cells, an oligomer consisting of 2,5-dioctyloxyphenylene(OP), 3-hexylthiophene(HT), and 2,3-dimethylthieno[ 3,4-b]pyrazine(TP) as repeat units, oligo(OP-HT-TP), was synthesized. The oligomer was amorphous in nature in the temperature range studied, and well soluble in common organic solvents such as chloroform. The maximum absorption wavelength was 716 nm in solid state. The band-gap and HOMO/LUMO energy levels of oligo(OP-HT-TP) were measured to be 1.20 eV and -5.27/4.04 eV, respectively. However, the absorbance of the oligomer at maximum absorption wavelength was less than one fifth of that of poly(3-hexylthiophene) which has been most frequently used in fabrication of organic solar cells.

• Bulletin of the Korean Chemical Society
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• v.19 no.3
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• pp.299-307
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• 1998

PM3 semiempirical calculations were carried out to study the frequency-dependent nonlinear optical properties of thiophene, furan, pyrrole, (1,2,4)-triazole, (1,3,4)-oxadiazole, and (1,3,4)-thiadiazole monomers and oligomers. The longitudinal component, αxx, is the largest of three principle components. On the other hand, the out-of-plane component, αzz, is the smallest. Moreover, the out-of-plane component (αzz) of thiophene, furan, pyrrole, (1,2,4)-triazole, (1,3,4)-oxadiazole, and (1,3,4)-thiadiazole monomers show constant changes with increasing optical frequencies. The frequency-dependent first- order polarizabilities increase in the order: thiophene > (1,2,4)-triazole > pyrrole > furan > (1,3,4)-thiadiazole > (1,3,4)-oxa-diazole monomers and oligomers. The effects of β(-2ω;ω,ω) (SHG) shows a larger dispersion compared with (-ω;ω,0) (EOPE) and β(0;-ω,ω) (OR). The second- order polarizabilities of thiophene, furan, pyrrole, (1,2,4)-triazole, (1,3,4)-thiadiazole, and (1,3,4)-oxadiazole monomers for the various second- order effects have the order: β(-2ω;ω,ω) (SHG) > β(-ω;ω,0) (EOPE) > β(0;-ω,ω) (OR) and thiophene > pyrrole > (1,2,4)-triazole > furan > 1,3,4-thiadiazole > 1,3,4-oxadiazole monomers. The third- order polarizabilities for the various third- order effects have the following order: γ(-3ω;ω',ω,ω) (THG) > γ(-2ω;0,ω,ω) (EFISHG) > γ(-ω;ω',-ω,ω) (IDRI) > γ(-ω;0,0,ω) (OKE). The effects of THG increase rapidly with increasing optical frequencies compared with the other effects. In particular, OKE effects increase most slowly with increasing optical frequencies. Also, the effects of THG for thiophene, furan, pyrrole, (1,2,4)-triazole, (1,3,4)-thiadiazole, and (1,3,4)-oxadiazole oligomers show the order thiophene > (1,2,4)-triazole > furan > pyrrole > (1,3,4)-thiadiazole > (1,3,4)-oxadiazole oligomers. In particular, the third- order polarizabilities of thiophene and (1,3,4)-thiadiazole oligomers are about four and three times larger than those of (1,3,4)-oxadiazole and (1,2,4)-triazole oligomer, respectively.

• Journal of the Korean Applied Science and Technology
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• v.16 no.4
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• pp.313-316
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• 1999

Organic semiconductors based on conjugated thiophene oligomer have great potential to be utilized as an active layer for electronic and optoelectronic devices. In this study, a conjugated oligomer such as ${\alpha}$-sexithiophene (${\alpha}$-6T) thin films was prepared by the Organic Molecular Beam Deposition (OMBD), and various electrode materials were also deposited by a simple vacuum evaporation, respectively. Those films were photolithographically patterned for the electrical measurements. Electrical charact-erization of the thin film transistor with various channel length were executed and the field effect mobility of these thin film transistors were also calculated by the formula using the experimental data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.313-316
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• 1998

Conjugated oligomers have been already used as active layers in field effect transistors, photodiodes and electroluminescent devices. Particularly thiophene oligomers such $\alpha$ -sexithiophene($\alpha$-6T) attract great interest for its prospective app1ications in large-area flexible displays. In this study, we investigated the contact properties between the organic semiconductor $\alpha$-6T and metals such as Au(Gold), Ag(Silver), Cr(Chromium), Al(Aluminum), Cr(Chromium). Using the Transmission Line Model(TLM) method, specific contact resistances of the metal lines in contact with the $\alpha$-6T were determined. From the current-voltage characteristics, electrical conductivity of the $\alpha$-6T films is found.

• Bulletin of the Korean Chemical Society
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• v.28 no.11
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• pp.1931-1938
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• 2007

Analyzed are recent advances in design of novel boronared conjugates of synthetic and natural porphyrins and chlorins. These compounds showed high efficacy as cytotoxic agents for tumor cells in culture and as phototoxins in photodynamic therapy of tumor xenografts. Thus, boronated porphyrins and chlorins emerge as promising class of anticancer agents with potentially multiple advantages: the chemotherapeutic drugs alone and photo- and radiosensitizers in binary treatments.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.586-589
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• 1999

Organic semiconductors based on conjugated thiophene oligomer have great potential to be utilized as an active layer far electronic and optoelectronic devices. In this study, $\alpha$ -sexithiophene($\alpha$-6T) thin films and various electrode materials were deposited by Organic Molecular Beam Deposition(OMBD) and vacuum evaporation respectively. Those films were photolithographically patterned fur measurements. Electrical characterization of the thin film transistor with various channel length were measured, and field effect mobility is calculated by formula.