http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Optical properties of porphyrin analogues for solar cells: An NLO approach
Mannix P. Balanay,Dong Hee Kim 한국물리학회 2011 Current Applied Physics Vol.11 No.1
The geometries, electronic structures, and optical properties of various β-substituted Zn tetraarylporphyrin analogues were studied using density functional theory (DFT). Major differences in geometry and electronic properties were observed as a function of the acceptor moiety. Analogues containing cyanoacrylic acid had longer Zn―N21 bonds, narrower band gaps, and more stabilized energy levels than their methylenemalonic counterparts. Nonlinear optical (NLO) properties were calculated using the Finite Field approach; they were influenced by the strengths of the donor and acceptor moieties and the length of the π-spacer group. The NLO response for all analogues was dominated by only one tensor component, indicating unidirectional charge transfer. The NLO results correlated well with the observed photo-to-current efficiencies provided that the analogues in comparison have the same π-conjugation length.
Mannix P. Balanay,Se-Mi Kim,Mi Jung Lee,이상희,김동희 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.9
The conformational and electronic properties of 2-cyano-3-(thiophen-2-yl)acrylic acid (TCA) in analogues used as sensitizers in dye-sensitized solar cells was examined using density functional theory (DFT) and natural bond orbital analysis methods. A relaxed potential energy surface scan was performed on NKX-2677 by rotating the C-C bond between the thiophene and cyanoacrylic acid which yielded activation energy barriers of about 13 kcal/mol for both E and Z configurations. The most stable conformation of all the analogues was E-180 except for NKX-2587 which has an electrostatic repulsion between the oxygen of the coumarin and the nitrogen of the cyanoacrylic acid. The increase in the electron delocalization between the thiophene and cyanoacrylic acid influences the stability for most of the analogues. But for NKX-2600, even though there was a greater deviation from the planarity of TCA, the stability was mainly due to the presence of a weak hydrogen bond between the hydrogen of the methyl group of the amine located in the donor moiety and the nitrogen of the cyanoacrylic acid. The vertical excitation energies of the analogues containing TCA were calculated by time-dependent DFT method. There were slight differences in its vertical excitation energies but the oscillator strengths vary significantly especially in the case of NKX-2600.
Strategic Design of Bacteriochlorins as Possible Dyes for Photovoltaic Applications
Balanay, Mannix P.,Kim, Dong Hee American Chemical Society 2017 The Journal of physical chemistry A Vol.121 No.35
<P>Bacteriochlorin-based dyes, having a push-pull type of configuration similar to that of the YD2 dye, were theoretically designed based on modification of the macrocycle and pi-conjugated bridge for use in dye-sensitized solar cells. Various parameters were assessed to determine its structure-property relationships, such as the absorption profile based on time-dependent density functional theory, nonlinear optical properties from (hyper)polarizability data, ground- and excited-state oxidation potentials, and the electronic properties of the free and adsorbed dyes. On the basis of the results, the most appropriate macrocycle would be 7,7,17,17-tetramethy1-7H,8H,17H,18H-porphyrin and, for its pi-conjugated bridge, either thieno[3,2-b]thiophene, dithieno[3,2-b:2',3'-d]-thiophene, or 4,4-diisopropy1-4H-cyclop enta [2,1-b:3,4-b'] dithiophene. These newly designed dyes produced an absorption spectra having a range of 300-800 nm, which could likely increase the light harvesting efficiency. It has better nonlinear properties than the reference, thereby ensuring higher charge-transfer properties. Also, the dye regeneration efficiency is within the optimized value of 0.2 of voltage. This shows that through theoretical approach we can deductively design process in the design of dyes to produce efficient dye-sensitized solar cells.</P>
Balanay, Mannix P.,Kim, Se-Mi,Lee, Mi-Jung,Lee, Sang-Hee,Kim, Dong-Hee Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.9
The conformational and electronic properties of 2-cyano-3-(thiophen-2-yl)acrylic acid (TCA) in analogues used as sensitizers in dye-sensitized solar cells was examined using density functional theory (DFT) and natural bond orbital analysis methods. A relaxed potential energy surface scan was performed on NKX-2677 by rotating the C-C bond between the thiophene and cyanoacrylic acid which yielded activation energy barriers of about 13 kcal/mol for both E and Z configurations. The most stable conformation of all the analogues was E-180 except for NKX-2587 which has an electrostatic repulsion between the oxygen of the coumarin and the nitrogen of the cyanoacrylic acid. The increase in the electron delocalization between the thiophene and cyanoacrylic acid influences the stability for most of the analogues. But for NKX-2600, even though there was a greater deviation from the planarity of TCA, the stability was mainly due to the presence of a weak hydrogen bond between the hydrogen of the methyl group of the amine located in the donor moiety and the nitrogen of the cyanoacrylic acid. The vertical excitation energies of the analogues containing TCA were calculated by time-dependent DFT method. There were slight differences in its vertical excitation energies but the oscillator strengths vary significantly especially in the case of NKX-2600.
Gnana kumar, G.,Balanay, Mannix P.,Nirmala, R.,Kim, Dong Hee,Raj kumar, T.,Senthilkumar, N.,Kim, Ae Rhan,Yoo, Dong Jin American Scientific Publishers 2016 Journal of Nanoscience and Nanotechnology Vol.16 No.1
<P>The PVdF-HFP nanofiber membranes with different molecular weight were prepared by electrospinning technique and were investigated as solid state electrolyte membranes in quasi solid state dye sensitized solar cells (QS-DSSC). The homogeneously distributed and fully interconnected nano fibers were obtained for all of the prepared PVdF-HFP electrospun membranes and the average fiber diameters of fabricated membranes were dependent upon the molecular weight of polymer. The thermal stability of electrospun PVdF-HFP membrane was decreased with a decrement of molecular weight, specifying the high heat transfer area of small diameter nanofibers. The QS-DSSC fabricated with the lower molecular weight PVdF-HFP electrospun nanofiber membrane exhibited the power conversion efficiency of n = 5.38%, which is superior over the high molecular weight membranes and is comparable with the liquid electrolyte. Furthermore, the electrospun PVdF-HFP membrane exhibited long-term durability over the liquid electrolyte, owing to the higher adsorption and retention efficiencies of liquid electrolyte in its highly porous and interconnected nanofibers. Thus the proposed electrospun PVdF-H FP membrane effectively tackled the volatilization and leakage of liquid electrolyte and provided good photoconversion efficiency associated with an excellent stability, which constructs the prepared electrospun membranes as credible solid state candidates for the application of QS-DSSCs.</P>