01905nas a2200169 4500008004100000022001400041245012300055210006900178260007500247300001200322490000600334520118700340100002501527700002401552700003001576856012901606 2016 eng d a1614-683200aBand edge modulated polymer layer to decrease back electron transfer and increase efficiency in sensitized solar cells0 aBand edge modulated polymer layer to decrease back electron tran aPOSTFACH 101161, 69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcMAY a15023340 v63 a

Recombination of charges residing in the TiO2 and redox electrolyte is one of the factors affecting the efficiency of dye sensitized solar cells (DSSCs). To circumvent this recombination, inorganic oxide barrier layers and organic silanes have been coated on TiO2/dyes. Due to the insulating nature of these layers, the efficiency increase is not very impressive. Conducting polymers with different band edges are used to suppress the charge recombination. Amongst the four polymers that are used as barrier layers, a polymer with a highest occupied molecular orbital energy at -5.8 eV and lowest unoccupied molecular orbital at -3.1 eV is found to increase the electron life time at TiO2 and decrease the charge recombination. The electron life time is found to be 88 ms. In addition to the long electron life time, the recombination resistance of this polymer is also high (91 Omega). This resistance is 18% higher than that measured for DSSCs without polymer barrier layer. These factors impact the efficiency of DSSCs. DSSCs fabricated with this polymer as barrier layer exhibit an efficiency of 9.2%, which is 22% higher than that of DSSCs without polymer barrier layer.

1 aArulkashmir, Arulraj1 aSudhakar, Vediappan1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/band-edge-modulated-polymer-layer-decrease-back-electron-transfer-and-increase-efficiency01635nas a2200169 4500008004100000245014100041210006900182260000800251300001400259490000700273520096500280100001601245700002201261700002401283700003001307856012801337 2016 eng d00aSynthesis and characterization of simple cost-effective trans-A(2)BC porphyrins with various donor groups for dye-sensitized solar cells0 aSynthesis and characterization of simple costeffective transA2BC cJUL a5704-57130 v403 aWe have designed and synthesized a series of simple cost-effective 'push-pull' Zn(II) porphyrin dyes containing various electron donors such as 2-thienyl, pyrenyl, phenyl, 4'-bromophenyl, 4'-tbutylphenyl and 4'-carboxyphenyl acceptor moieties in three steps. Their optical absorption spectra, electrochemical redox and photovoltaic properties have been investigated in detail. The overall power conversion efficiencies (Z) of DSSCs based on these dyes are in the range of 2.1 to 4.2% and highly depend on their donor moiety. The incorporation of trans-10,20-dimesityl groups is highly beneficial for preventing the p-p aggregation among the porphyrin moieties, thus favorably suppressing the charge recombination and intermolecular interaction. Among all, pyrenyl appended Zn(II) porphyrin has exhibited a higher power conversion efficiency of 4.2% under 1 sun illumination due to the extended p-conjugation and electron donating ability of the pyrenyl moiety.1 aKumar, Ravi1 aSankar, Muniappan1 aSudhakar, Vediappan1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/synthesis-and-characterization-simple-cost-effective-trans-a2bc-porphyrins-various-donor02605nas a2200181 4500008004100000245018600041210006900227260000800296300001600304490000600320520182500326100002402151700002402175700003902199700002802238700002702266856013002293 2017 eng d00aOrthogonally functionalized donor/acceptor homo- and heterodimeric dyes for dye-sensitized solar cells: an approach to introduce panchromaticity and control the charge recombination0 aOrthogonally functionalized donoracceptor homo and heterodimeric cOCT a34875-348900 v93 aOrganic dyes possessing conjugated pi-framework forms closely packed monolayers on photoanode in dye-sensitized solar cell (DSSC), because of the limitation to control the orientation and the extend of intermolecular pi-pi interaction, self-aggregation of dyes leads to reduced cell performance. In this report, a series of homodimeric (D-1-D-1, and D-2,-D-2) and heterodimeric (D-1-D-2 and D-2-D-4) donor/acceptor (D/A) dyes containing spiroBiProDOT pi-spacer were designed and synthesized by utilizing Pd-catalyzed direct arylation reaction and correlates the device performance with monomeric dyes (D-1 and D-2). Both the thiophenes (pi-spacer) of spiroBiProDOT were functionalized with same or different donor groups which led to homodimeric and heterodimeric chromophores in a single sensitizer. The homodimeric spirodye D-1-D-1 showed higher power conversion efficiency (PCE), of 7.6% with a V-oc and J(sc) of 0.672 V and 16.16 mA/cm(2), respectively. On the other hand, the monomeric D-1 exhibited a PCE of 3.2% (V-oc of 0.64 V and J(sc) of 7.2 mA/cm(2)); which is lower by 2.4 fold compared to dimeric analogue. The spiro-unit 20 provides flexibility between the incorporated chromophores to orient on TiO2 due to four sp(3)-centers, which arrest the molecular motions after chemisorption. This study shows a new molecular approach to incorporate two chromophores in the dimeric dye possessing complementary absorption characteristics toward panchromatic absorption. The attenuated charge recombination at TiO2/Dye/redox couple interface in case of D-1-D-1, owing to better passivation of TiO2 surface, was elucidated through impedance analysis. The FT-IR spectrum of D,-D, adsorbed on TiO2 film indicated both the carboxylic units were involved in chemisorption which makes strong coupling between dye and TiO2.1 aSil, Manik, Chandra1 aSudhakar, Vediappan1 aKavungathodi, Munavvar, Fairoos Me1 aPunitharasu, Vellimalai1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/orthogonally-functionalized-donoracceptor-homo-and-heterodimeric-dyes-dye-sensitized-solar00860nas a2200157 4500008004100000245012600041210006900167260000800236300001400244490000700258520022600265100002400491700002500515700003000540856013200570 2017 eng d00aPolymer and graphene layer to increase dye regeneration and suppress back electron transfer in dye sensitized solar cells0 aPolymer and graphene layer to increase dye regeneration and supp cJUN a6629-66320 v533 aDye regeneration was improved by using an optimum quantity of graphene, which was dispersed in a polymer that suppresses back electron transfer. Using this approach, DSSCs with an efficiency of 10.4% have been fabricated.1 aSudhakar, Vediappan1 aArulkashmir, Arulraj1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/polymer-and-graphene-layer-increase-dye-regeneration-and-suppress-back-electron-transfer-dye02581nas a2200265 4500008004100000022001400041245010200055210006900157260000800226300001600234490000700250520165100257653003101908653002401939653003001963653001901993653003002012653001902042100001802061700002402079700003902103700001902142700002702161856012702188 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 uhttps://library.ncl.res.in/content/fused-fluorenylindolenine-donor-based-unsymmetrical-squaraine-dyes-dye-sensitized-solar02831nas a2200193 4500008004100000022001500041245013300056210006900189260000800258300001400266490000700280520208100287100002402368700002402392700002702416700003902443700002702482856012802509 2018 eng d a 2192-650600a Homo- and heterodimeric dyes for dye-sensitized solar cells: panchromatic light absorption and modulated open circuit potential0 aHomo and heterodimeric dyes for dyesensitized solar cells panchr cNOV a 998-10070 v833 aThe design of dyes for panchromatic light absorption has attracted much attention in the field of dye-sensitized solar cells (DSSCs). An approach to enhance panchromatic light absorption utilizes mixtures of complementary light-absorbing dyes as well as dyes with specific anchoring groups that facilitate interfacial charge transfer with TiO2. Dipole-dipole interactions between the dye molecules on the surface broaden the spectrum, which results in decreased DSSC device performance. However, controlled aggregation of dyes results in broadening the spectral profile along with enhanced photocurrent generation. To control the dye-dye interaction, dimeric dyes with different dipole lengths D-1-D-sq, D-sq-D(sq)were systematically designed and synthesized. The photophysical and electrochemical properties were evaluated and the E-HOMO and E-LUMO levels were determined; these energy levels determines the electron injection from E-LUMO of the dye to E-CB of TiO2 and regeneration of oxidized dye by the electrolyte, respectively. The absorption spectra of D-sq-D-sq, D-1-D-sq were broadened in solution compared to model dye D-sq; this indicates that the dye-dye interaction is prominent in solution. In D-1-D-sq excitation energy transfer between photoexcited D-1 and D-sq was explained by using Forster resonance energy transfer (FRET). The homodimeric dye showed a device performace of 2.8 % (V-oc 0.607, J(sc) 6.62 mA/cm(2), ff 69.3 %),whereas the heterodimeric dye D-1-D-sq showed a device performance of 3.9 % (V-oc 0.652 V, J(sc) 8.89 mA/cm(2), ff 68.8 %). The increased photocurrent for D-1-D(sq)is due to the panchromatic IPCE response compared to D-sq-D-sq. The increased V(oc)is due to the effective passivation of the TiO2 surface by the spirolinker, and the effective dipole moment that shifts the conduction band on TiO2. Hence, the open circuit potential, V-oc, for the devices prepared from D-sq, D-1-D-sq and D-sq-D(sq)were systematically modulated by controlling the intermolecular pi-pi and intramolecular dipole-dipole interactions of the dimeric dyes.1 aSil, Manik, Chandra1 aSudhakar, Vediappan1 aSingh, Ambarish, Kumar1 aKavungathodi, Munavvar, Fairoos Me1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/homo-and-heterodimeric-dyes-dye-sensitized-solar-cells-panchromatic-light-absorption-and01695nas a2200217 4500008004100000022001400041245008100055210006900136260000800205300001400213490000600227520098600233653002201219653001601241653001801257653002301275100002401298700001901322700003001341856010601371 2018 eng d a2365-654900aSilk cocoon as counter - electrode substrate in dye - sensitized solar cells0 aSilk cocoon as counter electrode substrate in dye sensitized sol cJUL a7195-71990 v33 a

Electrodes are vital components of energy conversion devices such as dye sensitized solar cells (DSSCs). The widely used electrodes consist of fluorine doped tin oxide (FTO) and platinum. We were interested in identifying a substrate that is available from natural resources and exhibit performance comparable to that of Pt coated FTO (Pt-FTO). Silk fibers are naturally available and they are mechanically stable. The woven silk fibers are known as silk cocoons (SCs) that structurally resemble widely used carbon paper electrodes. To impart conductivity to the insulating SCs, metal film was coated by an electroless metal plating procedure using polyphenols from green tea. The metal coated SCs were conformaly coated with a conjugated polymer and these electrodes were used as flexible electrodes in DSSCs. The flexible electrode based DSSCs exhibited a power conversion efficiency of 7.2% which is comparable to that of the DSSCs with rigid Pt-FTO based devices (7.4%).

10acounter electrode10aPEDOT-G-SCs10aRecombination10aSilk cocoons (SCs)1 aSudhakar, Vediappan1 aDas, Chayanika1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/silk-cocoon-counter-electrode-substrate-dye-sensitized-solar-cells01694nas a2200157 4500008004100000022001400041245007200055210006900127260000900196300001600205490000600221520116200227100002401389700003001413856009301443 2019 eng d a2050-752600aEnhancing the device efficiency by filling the traps in photoanodes0 aEnhancing the device efficiency by filling the traps in photoano cDEC  a14632-146380 v73 a

Traps are ubiquitous in semiconductors and act as recombination sites. These recombination sites have a deleterious effect on the device efficiency. Thus, trap filling is used to increase the efficiency of devices. The traps are filled by dopants that either inject or extract electrons to/from the semiconductor. The trap-filled devices exhibit superior performance as compared to their unfilled counterparts. However, to date, this approach has not been explored in dye-sensitized solar cells despite the well-established presence of traps in them. The traps in the TiO2 photoanode are due to the presence of oxygen vacancies. Therefore, herein, we treated the photo anodes with hydrazine and filled the traps that increased all device metrics. Moreover, further sintering of the trap-filled photoanodes in the presence of hydrazine led to the formation of a nitrogen-doped photoanode. The device comprising a nitrogen-doped photoanode exhibited the efficiency increase of 23%. The detailed analysis of the device performance led to the conclusion that trap filling suppressed back electron transfer and increased the photo conversion efficiency.

1 aSudhakar, Vediappan1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/enhancing-device-efficiency-filling-traps-photoanodes02541nas a2200253 4500008004100000022001400041245016400055210006900219260000800288300001400296490000800310520162600318653003101944653002001975653001901995653000802014100002802022700002002050700002002070700002402090700003002114700002102144856012202165 2019 eng d a0169-433200aEvolution of ZnO nanostructures as hexagonal disk: Implementation as photoanode material and efficiency enhancement in Al: ZnO based dye sensitized solar cells0 aEvolution of ZnO nanostructures as hexagonal disk Implementation cMAR a1130-11380 v4703 a

Hexagon shaped pristine and Al doped ZnO nanodisks (NDs) with exposed +/- [0001] polar facets were successfully synthesized using modified sol-gel method without the involvement of any structural directing or capping agents. It was investigated that OH- ions in mixed solvent system is responsible for pore formation and inhibit the growth of ZnO along the direction of c-axis leading to a high percentage exposure of active +/- [0001] polar facets and encourage the formation of ZnO NDs. Crystallographic analysis revealed that crystallite size and lattice constants are decreased, with the addition of Al3+ ions. The results obtained from Raman, and XPS analysis further corroborated with the XRD results, revealed the successful incorporation of Al3+ ions into ZnO lattice. Optical study revealed the band gap tunability with the incorporation of Al ion as dopant. Enhanced power conversion efficiency (PCE) of 1.96% (J(sc) similar to 7.69 +/- 0.23 mA/cm(2)) was observed for Al: ZnO hexagonal NDs based DSSC. The increased PCE in Al: ZnO based DSSC can be attributed to the higher inner surface area for dye anchoring by the interconnected network of the disk-like structure. The obtained results were satisfactory and most importantly the synthesis procedure proposed in present work is excellent for the synthesis of perfectly hexagonal shaped disks under precised synthesis parameters. The device interface study was further conducted using electrochemical impedance spectroscopy which revealed better charge transport process and charge storage ability with the incorporation of Al3+ ions into ZnO lattice.

10adye sensitized solar cells10aHexagonal disks10aSol-gel method10aZnO1 aParra, Mohammad, Ramzan1 aPandey, Padmini1 aSiddiqui, Hafsa1 aSudhakar, Vediappan1 aKrishnamoorthy, Kothandam1 aHaque, Fozia, Z. uhttps://library.ncl.res.in/content/evolution-zno-nanostructures-hexagonal-disk-implementation-photoanode-material-and02050nas a2200181 4500008004100000022001400041245014200055210006900197260000800266300001200274490000800286520135400294100001901648700002401667700002201691700003001713856012501743 2019 eng d a0143-720800aTrans-A(2)B(2) Zn(II) porphyrin dyes with various donor groups and their Co-sensitization for highly efficient dye-sensitized solar cells0 aTransA2B2 ZnII porphyrin dyes with various donor groups and thei cJAN a386-3940 v1603 a

{We have designed and synthesized four donor-acceptor based trans-A(2)B(2) Zn(II) porphyrin dyes with various donor moieties and phenylcarboxy as acceptor group in three steps. Two strong electron-donating groups (carbazole, phenothiazine, pyrene and bisthiophene) were attached to porphyrin core to enhance the light absorption of dye molecules and phenylcarboxy acted as acceptor group on TiO2 surface. The alkyl chains present in KP-Zn-CBZ and KP-Zn-PTZ dyes are helpful to suppress the aggregation of dyes at the semiconductor surface. The synthetic route of these dyes was facile, high yield and three steps procedure which involved MacDonald condensation followed by hydrolysis and Zn insertion. The absorption and emission bands of all four dyes were broadened and red shifted due to the charge transfer from donor groups to porphyrin moiety. A wide range of power conversion efficiency was shown by dyes and the order of eta was as followed KP-Zn-PTZ (5.48%) > KP-Zn-PYR (3.38%) > KP-Zn-CBZ (2.64%) > KP-Zn-BTP (1.71%). Co-sensitization of porphyrin dyes with N719 dye promoted the complementary absorption in the visible region and put a restriction on dye aggregation also which improved the cell performance. Co-sensitized KP-Zn-PTZ with N719 dye showed the highest PCE efficiency up to 8.80% with a J(SC) = 17.4 mA cm(-2)

1 aPrakash, Kamal1 aSudhakar, Vediappan1 aSankar, Muniappan1 aKrishnamoorthy, Kothandam uhttps://library.ncl.res.in/content/trans-a2b2-znii-porphyrin-dyes-various-donor-groups-and-their-co-sensitization-highly01665nas a2200277 4500008004100000022001400041245010500055210006900160260000900229300001200238490000800250520078100258653002001039653000901059653002301068653001301091653002101104653000901125100002501134700001601159700001601175700002401191700003001215700001801245856012401263 2020 eng d a0038-092X00aAromatic amine passivated TiO2 for dye-sensitized solar cells (DSSC) with similar to 9.8% efficiency0 aAromatic amine passivated TiO2 for dyesensitized solar cells DSS cMAY  a965-9710 v2013 a

In this work, the efficiency of dye-sensitized solar cells (DSSC) was improved by capping TiO2 with simple aromatic amines as a complexing agent. The aromatic amines, aniline and o-phenylenediamine capped TiO2 composites were synthesized via hydrothermal route and used as scattering layer in dye-sensitized solar cell (DSSC). Markedly, the maximum photo-conversion efficiency of 9.84% was achieved with o-phenylenediamine capped-TiO2 composite as o-phenylenediamine capped-TiO2 showed higher reflectivity than the pristine TiO2, which is highly beneficial for reflecting the photons back to photoanode. In addition, the average life time of carriers in o-phenylenediamine capped-TiO2 was found to be 9.8 ms, which was 2 times higher than the pristine TiO2 (4.29 ms).

10aAromatic amines10aDSSC10aElectron injection10alifetime10aScattering layer10aTiO21 aKumar, T., R. Naveen1 aYuvaraj, S.1 aKavitha, P.1 aSudhakar, Vediappan1 aKrishnamoorthy, Kothandam1 aNeppolian, B. uhttps://library.ncl.res.in/content/aromatic-amine-passivated-tio2-dye-sensitized-solar-cells-dssc-similar-98-efficiency02005nas a2200229 4500008004100000022001400041245012300055210006900178260000800247300001200255490000600267520117600273653002201449653003101471653003001502653001401532653002701546100002401573700002301597700002601620856012901646 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 uhttps://library.ncl.res.in/content/nanoporous-reduced-graphene-oxide-and-polymer-composites-efficient-counter-electrodes-dye02357nas a2200217 4500008004100000022001400041245006200055210006200117260000800179300001200187490000800199520169200207653001801899653002001917653001901937653002801956653001401984100002301998700002402021856009402045 2021 eng d a0957-582000aHighly efficient method of utilizing waste silica hazards0 aHighly efficient method of utilizing waste silica hazards cSEP a239-2480 v1533 aSilica gels are the significant commodity solid waste produced by organic laboratories and pharmaceutic industries. Although use of silica gels is continuously growing, the proper methods of re-utilizing silica waste are yet limited. Hence, it demands a non-traditional approach to transform these silica waste into some other useful products apart from using them as a well-known road construction materials. Hereby, we report the fabrication and applications of monolithic polymer-silica composites by ice-templating technique from laboratory waste silica-gels, using green approach. To the best of our knowledge, the fabrication of organic-inorganic hybrid sponges from the particles of hundreds of microns is not reported to date. Scaffolds S-60, S-120, S-180, and S-300, were prepared from laboratory discarded silica gels. The morphological, physicochemical, flame-retardant, and liquid absorbent properties of these self-standing scaffolds were analyzed. Results showed that the incorporation of silica particles in the scaffolds turned them into a flame-retardant sponge. These properties make the sponges ideal for making non-flammable cushions, applicable in automobiles, aircrafts, chemical laboratories, hospitals, and other areas of applications. Due to the large porous structures, these scaffolds possess excellent absorption properties and may absorb almost every kind of liquid ranging from oils to acids. Therefore, these scaffolds are also a remarkable absorber for oils and hazardous liquids spillage, such as acids, and can be used as foam for chemical packing applications. (C) 2021 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.10aAcid absorber10aFlame-retardant10aIce-templating10aLaboratory silica waste10ascaffolds1 aSingh, Anup, Kumar1 aSudhakar, Vediappan uhttps://library.ncl.res.in/content/highly-efficient-method-utilizing-waste-silica-hazards02030nas a2200253 4500008004100000022001400041245010900055210006900164260000800233490000600241520111800247653002201365653002701387653003101414653001701445653003201462100002701494700002401521700003401545700001801579700003001597700002701627856012201654 2023 eng d a2367-093200aModular TiO2-squaraine dyes/electrolyte interface for dye-sensitized solar cells with cobalt electrolyte0 aModular TiO2squaraine dyeselectrolyte interface for dyesensitize cAPR0 v73 a

Strategies to diminish both charge recombination and aggregation of dyes on the photoanode by functionalizing the sensitizer with alkyl groups is the best approach to achieve high dyesensitized solar cell (DSSC) efficiency. Development of such a photoanode with NIR-active dyes which is compatible with a cobalt electrolyte is important to enhance the photovoltaic performance. In this report, alkyl-group-wrapped donor-acceptor-donor (D-A-D) based unsymmetrical squaraine dyes have been used for DSSC device characterization with a cobalt electrolyte. Surface passivation of photoanode was varied systematically by the extent of functionalization with alkyl groups to avoid charge recombination. DSSC device performance of 5.92% was achieved for an alkyl-group-wrapped squaraine dye with a cobalt electrolyte. Hence, appending the alkyl groups on the donor unit of squaraine dyes helps passivating the photoanode, whereas introducing hydrophilic groups provides a leaky surface where oxidized electrolyte species reach the titanium-metal-oxide surface which promotes the charge recombination process.

10acounter-electrode10aDSSC device efficiency10aDye-sensitized solar cells10aElectrolytes10aunsymmetrical squaraine dye1 aSingh, Ambarish, Kumar1 aSudhakar, Vediappan1 aJavaregowda, Bharathkumar, H.1 aBisht, Rajesh1 aKrishnamoorthy, Kothandam1 aNithyanandhan, Jayaraj uhttps://library.ncl.res.in/content/modular-tio2-squaraine-dyeselectrolyte-interface-dye-sensitized-solar-cells-cobalt