01748nas a2200289 4500008004100000022001400041245012700055210006900182260007100251300001400322490000600336520071700342653002101059653002001080653003101100653002101131653001701152100001801169700001601187700002001203700002101223700001701244700002201261700001901283700002501302856013101327 2009 eng d a1944-824400aEnhanced conversion efficiency in dye-sensitized solar cells based on hydrothermally synthesized TiO2-MWCNT nanocomposites0 aEnhanced conversion efficiency in dyesensitized solar cells base a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP a2030-20350 v13 a

A 50 % enhancement in the conversion efficiency (4.9-7.37 %) is realized in dye-sensitized solar cells Using hydrothermally synthesized TiO2-multiwalled carbon nanotube (MWCNT) nanocomposites as compared to hydrothermally synthesized TiO2 without MWCNT and Degussa P25. Several characterizations have been employed to reveal the nature of the modification imparted to the MWCNTs under hydrothermal processing conditions and the resulting TiO2-MWCNT conjugation through -COOH groups. Efficient charge transfer In the nanocomposite and efficient electron transport by MWCNT (significantly higher Incident-photon-to-current conversion efficiency) are suggested to be the possible reasons for the enhancement.

10aCarbon nanotubes10acharge transfer10aDye-sensitized solar cells10aHybrid composite10ahydrothermal1 aMuduli, Subas1 aLee, Wonjoo1 aDhas, Vivek, V.1 aMujawar, Sarfraj1 aDubey, Megha1 aVijayamohanan, K.1 aHan, Sung-Hwan1 aOgale, Satishchandra uhttp://library.ncl.res.in/content/enhanced-conversion-efficiency-dye-sensitized-solar-cells-based-hydrothermally-synthesized-001885nas a2200253 4500008004100000022001400041245008200055210006900137260010600206300001400312490000700326520094000333653003101273653004301304653001701347100002001364700001801384700002401402700002001426700002301446700002001469700002901489856011301518 2011 eng d a0038-092X00aEnhanced DSSC performance with high surface area thin anatase TiO2 nanoleaves0 aEnhanced DSSC performance with high surface area thin anatase Ti aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJUN a1213-12190 v853 a

Thin anatase TiO2 nanoleaves (NLs) with high surface area (similar to 93 m(2)/g) are synthesized by hydrothermal route and dye-sensitized solar cells (DSSC) made using such NLs are compared with those made with hydro-thermally synthesized TiO2 nanoparticles and the Degussa P25 powder. The NLs-based DSSCs show increment of 16% and 24% in the total conversion efficiency over the cells made with NPs and P25 respectively. Interestingly, the highest increment in the conversion efficiency (similar to 35%) is achieved for cells made using a 50:50 (wt/wt) mixture of NLs and NPs. In this case the dye loading is found to be >50% higher than the case of NP films. Moreover the DC resistance of diffusion of I-3(-) in electrolyte (as revealed by the electrochemical impedance spectroscopy) is substantially lower than the NP film case, other cell parameters being nominally comparable. (C) 2011 Elsevier Ltd. All rights reserved.

10aDye-sensitized solar cells10aElectrochemical impedance spectroscopy10ahydrothermal1 aDhas, Vivek, V.1 aMuduli, Subas1 aAgarkar, Shruti, A.1 aRana, Abhimanyu1 aHannoyer, Beatrice1 aBanerjee, Rahul1 aOgale, Satishchandra, B. uhttp://library.ncl.res.in/content/enhanced-dssc-performance-high-surface-area-thin-anatase-tio2-nanoleaves-001835nas a2200277 4500008004100000022001400041245009400055210006900149260010600218300001400324490000700338520084400345653001701189653000701206653003101213653002101244653001701265100001801282700002001300700002001320700002201340700002501362700001701387700002901404856012401433 2012 eng d a0038-092X00aTiO2-Au plasmonic nanocomposite for enhanced dye-sensitized solar cell (DSSC) performance0 aTiO2Au plasmonic nanocomposite for enhanced dyesensitized solar  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcMAY a1428-14340 v863 a

Anatase TiO2 nanoparticles dressed with gold nanoparticles were synthesized by hydrothermal process by using mixed precursor and controlled conditions. Diffused Reflectance Spectra (DRS) reveal that in addition to the expected TiO2 interband absorption below 360 nm gold surface plasmon feature occurs near 564 nm. It is shown that the dye sensitized solar cells made using TiO2-Au plasmonic nanocomposite yield superior performance with conversion efficiency (CE) of similar to 6% (no light harvesting), current density (J(SC)) of similar to 13.2 mA/cm(2), open circuit voltage (V-oc) of similar to 0.74 V and fill factor (FF) 0.61; considerably better than that with only TiO2 nanoparticles (CE similar to 5%, J(SC) similar to 12.6 mA/cm(2), V-oc similar to 0.70 V, FF similar to 0.56). (C) 2012 Elsevier Ltd. All rights reserved.

10aAnatase TiO210aAu10aDye-sensitized solar cells10aHybrid composite10ahydrothermal1 aMuduli, Subas1 aGame, Onkar, S.1 aDhas, Vivek, V.1 aVijayamohanan, K.1 aBogle, Kashinath, A.1 aValanoor, N.1 aOgale, Satishchandra, B. uhttp://library.ncl.res.in/content/tio2-au-plasmonic-nanocomposite-enhanced-dye-sensitized-solar-cell-dssc-performance-002184nas a2200241 4500008004100000022001400041245015900055210006900214260005700283300000800340490000700348520129500355653000801650653003101658653001701689653002001706653001101726100002401737700002001761700001701781700002301798856012101821 2016 eng d a1610-294000aDoes the position of the electron-donating nitrogen atom in the ring system influence the efficiency of a dye-sensitized solar cell? A computational study0 aDoes the position of the electrondonating nitrogen atom in the r a233 SPRING ST, NEW YORK, NY 10013 USAbSPRINGERcJUN a1210 v223 a

We have reported a number of new metal-free organic dyes (2-6) that have cyclic asymmetric benzotripyrrole derivatives as donor groups with peripheral nitrogen atoms in the ring, fluorine and thiophene groups as pi-spacers, and a cyanoacrylic acid acceptor group. Density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were employed to examine the influence of the position of the donor nitrogen atom and pi-conjugation on solar cell performance. The calculated electron-injection driving force (Delta G(inject)), electron-regeneration driving force (Delta G(regen)), light-harvesting efficiency (LHE), dipole moment (mu(normal)), and number of electrons transferred (Delta q) indicate that dyes 3, 4, and 6 have significantly higher efficiencies than reference dye 1, which exhibits high efficiency. We also extended our comparison to some other reported dyes, 7-9, which have a donor nitrogen atom in the middle of the ring system. The computed results suggest that dye 6 possesses a higher incident photon to current conversion efficiency (IPCE) than reported dyes 7-9. Thus, the use of donor groups with peripheral nitrogen atoms appears to lead to more efficient dyes than those in which the nitrogen atom is present in the middle of the donor ring system.

10aDFT10aDye-sensitized solar cells10aOrganic dyes10aPosition effect10aTD-DFT1 aBiswas, Abul, Kalam1 aBarik, Sunirmal1 aDas, Amitava1 aGanguly, Bishwajit uhttp://library.ncl.res.in/content/does-position-electron-donating-nitrogen-atom-ring-system-influence-efficiency-dye02580nas a2200265 4500008004100000022001400041245010200055210006900157260000800226300001600234490000700250520165100257653003101908653002401939653003001963653001901993653003002012653001902042100001802061700002402079700003902103700001902142700002702161856012602188 2018 eng d a1944-824400aFused fluorenylindolenine-donor-based unsymmetrical squaraine dyes for dye-sensitized solar cells0 aFused fluorenylindoleninedonorbased unsymmetrical squaraine dyes cAUG a26335-263470 v103 a

A series of four unsymmetrical squaraine dyes, XSQ1-4, were synthesized using a fused fluorenylindolenine-based donor unit for dye-sensitized solar cells (DSSCs). The fused structure of fluorenylindolenine helped in moving the absorption toward the near-infrared (NIR) region, and the two sp(3)-C centers available on this donor were utilized to incorporate out-of-plane alkyl chains in opposite directions to control the dye-dye interactions on the TiO2 surface. High extinction coefficient (epsilon >= 10(5) M-1 cm(-1)) for absorbing NIR photons and suitable highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels with respect to the conduction band of TiO2 and electrolyte for charge injection and dye regeneration processes, respectively, make these dyes potential sensitizers for DSSCs. Introduction of branched alkyl groups in the pi-framework helped in controlling dye aggregation to reduce exciton quenching and assisted in TiO2 surface passivation to avoid the charge recombination process. Furthermore, having a naphthyl group on the indole part of the anchoring group containing segment helped to red-shift the absorption spectrum of dyes 15 nm toward the NIR region (XSQ3-4). Among all of the dyes under investigation, XSQ2 gave the best photovoltaic performance, having a short-circuit current density (J(SC)) of 13.99 mA cm(-2), open -circuit voltage (V-OC) of 0.66 V, and a fill factor (ff) of 0.71, with a device performance (eta) of 6.57%. Electrochemical impedance spectroscopy revealed higher electron lifetime on TiO2 for XSQ2, which helps to avoid the charge recombination process.

10aDye-sensitized solar cells10afluorenylindolenine10aH- and J-type aggregation10aNIR absorption10aout-of-plane alkyl groups10asquaraine dyes1 aBisht, Rajesh1 aSudhakar, Vediappan1 aKavungathodi, Munavvar, Fairoos Me1 aKarjule, Neeta1 aNithyanandhan, Jayaraj uhttp://library.ncl.res.in/content/fused-fluorenylindolenine-donor-based-unsymmetrical-squaraine-dyes-dye-sensitized-solar02334nas a2200241 4500008004100000022001400041245011500055210006900170260000800239300001400247490000600261520145000267653002301717653002001740653003101760653003201791653002601823100002801849700003901877700002701916700002701943856012201970 2019 eng d a2574-096200api-Extended cis-configured unsynimetrical squaraine dyes for dye-sensitized solar cells: panchromatic response0 apiExtended cisconfigured unsynimetrical squaraine dyes for dyese cDEC a8464-84720 v23 a

{Light absorbing sensitizer is the heart of the third generation photovoltaic technologies such as dye sensitized solar cells. Despite possessing large extinction coefficients for the metal-free organic dyes, the light harvesting efficiency is limited with the narrow absorption 20 profile in either visible or NIR regions of the solar spectrum. Though monolayer formation of organic sensitizers on semiconducting metal oxide surface leads to dye-dye interaction that leads to broadening the absorption profile, the contribution of the aggregated state to the power conversion process is found out to be poor. Here, we have engineered far-red active pi-extended cis-configured unsymmetrical squaraine dyes with carboxylic acid and cycnoacetic acid as anchoring groups with controlled aggregation and panchromatic light absorption by including the steric and electronic factors. The presence of sp(3)-C (out-of-plane) and N-alkyl (in-plane) groups played an important role in modulating the assembly of the dyes on the TiO2 electrode; the cis-squaraine unit helps to extend the conjugation in the NIR region besides enhancing the visible transition and the incident photon-to-current conversion efficiency profile that showed the importance of anchoring groups for the panchromatic response. Dye PSQ10 showed solar-to electric conversion with an onset of 850 nm with the device performance of 7.0% (V-oc = 0.581 V, J(sc) = 17.06 mA/cm(2)

10acis-squaraine dyes10aDye aggregation10aDye-sensitized solar cells10aextended far-red absorption10apanchromatic response1 aPunitharasu, Vellimalai1 aKavungathodi, Munavvar, Fairoos Me1 aSingh, Ambarish, Kumar1 aNithyanandhan, Jayaraj uhttp://library.ncl.res.in/content/pi-extended-cis-configured-unsynimetrical-squaraine-dyes-dye-sensitized-solar-cells03101nas a2200229 4500008004100000022001400041245017500055210006900230260000800299300001400307490000700321520219200328653002302520653002102543653002502564653003102589653002902620100002702649700003902676700002702715856012902742 2020 eng d a1944-824400aAlkyl-group-wrapped unsymmetrical squaraine dyes for dye-sensitized solar cells: branched alkyl chains modulate the aggregation of dyes and charge recombination processes0 aAlkylgroupwrapped unsymmetrical squaraine dyes for dyesensitized cJAN a2555-25650 v123 a

Electron transfer processes at the interfaces dictate the factors that improve the photovoltaic parameters, such as open-circuit voltage (V-oc) and short-circuit current (J(sc)), of a dye-sensitized solar cell device, besides selection of a set of suitable anode, dye, electrolyte, and cathode materials. An inefficient charge injection process at the dye-TiO2 interface and charge recombination at the TiO2-dye/electrolyte interface have detrimental effects on improving both J(sc) and V-oc. Hence, tailoring the factors that govern the improvement of J(sc) and V-oc will be an ideal approach to get the desired sensitizers with good device efficiencies. Squaraines are far-red-active zwitterionic dyes and have a high molar extinction coefficient along with unique aggregation properties due to the large dipole moment associated with them. Here, we report a series of unsymmetrical squaraine dyes, SQS1 to SQS6, with systematic variation of alkyl groups at the sp(3)-C and N-atoms of the indoline unit that is away from the anchoring group to control the dye-dye interactions on the TiO2 surface. The branched alkyl groups help in modulating the self-assembly of sensitizers on the TiO2 surface, besides passivating the surface that helps avoid the charge recombination processes. Light harvesting efficiency and cyclic voltammetry studies of dye-sensitized TiO2 electrodes indicate that the aggregation and charge hopping process between the dye molecules can be modulated, respectively, by systematically increasing the number of carbon atoms in the alkyl groups. Such a variation in the branched alkyl group helps enhance V-oc from 672 (SQS1) to 718 mV (SQS6) and J(sc) from 7.95 (SQS1) to 12.22 mA/cm(2) (SQS6), with the device efficiency ranging from 3.82% to 6.23% without any coadsorbent. Dye SQS4 achieves the highest efficiency of 7.1% (V-oc = 715 mV, J(sc) = 13.05 mA/cm(2)) with coadsorbent chenodeoxycholic acid (CDCA) using an iodine (I-/I-3(-)) electrolyte compared to its analogues. An analysis of the incident photon-to-current efficiency profiles indicates that the major contribution to photocurrent generation is from the aggregated squaraine dyes on TiO2.

10aaggregation of dye10acharge injection10acharge recombination10aDye-sensitized solar cells10aunsymmetrical squaraines1 aSingh, Ambarish, Kumar1 aKavungathodi, Munavvar, Fairoos Me1 aNithyanandhan, Jayaraj uhttp://library.ncl.res.in/content/alkyl-group-wrapped-unsymmetrical-squaraine-dyes-dye-sensitized-solar-cells-branched-alkyl02004nas a2200229 4500008004100000022001400041245012300055210006900178260000800247300001200255490000600267520117600273653002201449653003101471653003001502653001401532653002701546100002401573700002301597700002601620856012801646 2020 eng d a2637-611300aNanoporous reduced graphene oxide and polymer composites as efficient counter electrodes in dye-sensitized solar cells0 aNanoporous reduced graphene oxide and polymer composites as effi cMAR a626-6340 v23 a

The introduction of an efficient and precious platinum (Pt) free counter electrode (CE) for dye-sensitized solar cells (DSSCs) is an important aspect to address. In this report, we have employed nanoporous reduced graphene oxide (PG) containing PEDOT:PSS-PG composite on FTO substrate as CEs, which have shown excellent diffusion of I-3(-), remarkable photocatalytic activity, and better device performance along with desired stability. The investigated cathode material has been prepared by mixing PGs and highly conducting PEDOT:PSS. Experimental measurements and analyses such as electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and so on indicate that PEDOT:PSS-PG is a promising cathode material for a Pt-free CE in DSSCs. EIS indicates that the PEDOT:PSS-PGs have lower interfacial charge-transfer resistance because of their high electrical conductivity and superior electrocatalytic activity. The achieved photoconversion efficiency (eta) of a DSSC employing the Pt-free PEDOT:PSS-PG/FTO CE is 9.57%, which is found to be comparable to that of Pt/FTO CE based DSSC (9.64%) under a simulated solar light illumination of 100 mW/cm(2).

10acounter electrode10aDye-sensitized solar cells10aelectrocatalytic activity10aPEDOT:PSS10aReduced graphene oxide1 aSudhakar, Vediappan1 aSingh, Anup, Kumar1 aChini, Mrinmoy, Kumar uhttp://library.ncl.res.in/content/nanoporous-reduced-graphene-oxide-and-polymer-composites-efficient-counter-electrodes-dye02668nas a2200229 4500008004100000022001400041245017400055210006900229260000800298300001400306490000600320520174000326653003102066653004102097653003502138653002702173653003402200653002002234100002702254700002702281856013002308 2022 eng d a2574-096200aIndoline-based donor-pi-acceptor visible-light responsive organic dyes for dye-sensitized solar cells: co-sensitization with squaraine dye for panchromatic IPCE response0 aIndolinebased donorpiacceptor visiblelight responsive organic dy cFEB a1858-18680 v53 a

A series of metal-free indoline-based donor-pi-acceptor (D-pi-A) visible-light active organic dyes, where an indoline unit wrapped with alkyl or alkyl and glycolic (TEG) groups is used as a donor, a mono- or bi-thiophene unit is used as a pi-spacer, and cyanoacrylic acid acts as an acceptor unit, have been designed and synthesized for dye-sensitized solar cell (DSSC) application. These dyes showed three absorption bands in a dichloromethane solution: the first and second transitions are observed in the UV (337-385 nm) and visible (477-514 nm) regions and correspond to pi-pi* and intramolecular charge transfer (ICT) transition, respectively, whereas the third absorption band obtained in the near-IR (629-758 nm) region has been observed for the first time for a D-pi-A type dye architecture. Furthermore, the ICT transition band for AKT dyes showed negative solvatochromism with increasing polarity of solvents. Photovoltaic characterizations for AKT dyes have been systematically studied with a cobalt electrolyte to evaluate the effect of thiophene incorporation and alkyl group substitution by the TEG group on the DSSC device performance. Here, AKT2 showed the highest DSSC efficiency of 3.16% with V-OC of 0.680 V and J(SC) of 6.24 mA/cm(2) without chenodeoxycholic acid (CDCA) in the AKT dye series, whereas DSSC efficiencies for AKT dyes were not affected much upon further addition of CDCA. Furthermore, AKT dyes were co-sensitized with a complementary optical responsive indoline-based SQS4 dye and showed enhanced efficiency. The combination of AKT2/SQS4 dyes with a ratio of 1:1 showed a maximum of 5.20% co-sensitized solar cell efficiency compared to other dye combinations with the cobalt electrolyte.

10aDye-sensitized solar cells10aindoline-based donor-pi-acceptor dye10aintramolecular charge transfer10ametal-free organic dye10apanchromatic-light absorption10aSolvatochromism1 aSingh, Ambarish, Kumar1 aNithyanandhan, Jayaraj uhttp://library.ncl.res.in/content/indoline-based-donor-pi-acceptor-visible-light-responsive-organic-dyes-dye-sensitized-solar01963nas a2200253 4500008004100000022001400041245011800055210006900173260000800242490000600250520107500256653002001331653001901351653003101370653002501401653001901426100001801445700002701463700001701490700001701507700003001524700002701554856012801581 2023 eng d a2367-093200aVisible-light-active unsymmetrical squaraine dyes with 1 V of open-circuit voltage for dye-sensitized solar cells0 aVisiblelightactive unsymmetrical squaraine dyes with 1 V of open cMAY0 v73 a

A series of alkyl-group-functionalized, aniline- and indoline-donor-based, unsymmetrical visible-light-active squaraine dyes, AM1-3, were designed and synthesized. Dye-sensitized solar cell (DSSC) devices were fabricated with both I-/I-3(-) and [Cu(tmby)(2)](+/2+) electrolytes. DSSC devices sensitized with the AM1 and AM2 dyes showed relatively high-power conversion efficiency of 7.44 % and 7.22 %, respectively with I-/I-3(-) in the absence of chenodeoxycholic acid (CDCA) than those of the AM3 dye (5.41 %). The [Cu(tmby)(2)](+/2+) electrolyte along with poly(3,4-ethylenedioxythiophene) (PEDOT) as cathode material showed excellent open-circuit potentials (V-OC) of 1030, 1025, and 1001 mV with the DSSC efficiency of 8.05 %, 7.96 %, and 5.84 %, respectively, for the AM1, AM2, and AM3 dyes in the absence of CDCA. Here, the AM1 dye exhibited the maximum DSSC efficiency of 8.05 % and V-OC of 1030 mV, which is the highest obtained efficiency and V-OC for the visible-light active zwitterionic unsymmetrical-squaraine dye with copper-based electrolyte.

10aCu electrolytes10adihedral angle10aDye-sensitized solar cells10aopen circuit voltage10asquaraine dyes1 aSingh, Amrita1 aSingh, Ambarish, Kumar1 aDixit, Ruchi1 aVanka, Kumar1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttp://library.ncl.res.in/content/visible-light-active-unsymmetrical-squaraine-dyes-1-v-open-circuit-voltage-dye-sensitized