01518nas a2200289 4500008004100000022001400041245013400055210006900189260012500258300002300383490000700406520041900413653003300832653000900865653002500874653001900899653001800918653001600936653003300952653001900985100002001004700001801024700001601042700001901058700002901077856012201106 2008 eng d a0003-695100aEnhanced conversion efficiency in dye-sensitized solar cells based on ZnO bifunctional nanoflowers loaded with gold nanoparticles0 aEnhanced conversion efficiency in dyesensitized solar cells base aCIRCULATION & FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USAbAMER INST PHYSICScDEC aArticle No. 2431080 v933 a

The ZnO nanoflowers loaded with gold (Au) nanoparticles (NPs) are synthesized by a hydrothermal route using mixed precursors and controlled conditions. The dye-sensitized solar cells based on the ZnO nanoflowers with Au NPs show power conversion efficiency of 2.5%, which is considerably higher than that of ZnO nanoflowers without Au NPs. Detailed characterizations are performed, presented, and discussed.

10acrystal growth from solution10aGold10aII-VI semiconductors10aNanocomposites10aNanoparticles10asolar cells10awide band gap semiconductors10azinc compounds1 aDhas, Vivek, V.1 aMuduli, Subas1 aLee, Wonjoo1 aHan, Sung-Hwan1 aOgale, Satishchandra, B. uhttps://library.ncl.res.in/content/enhanced-conversion-efficiency-dye-sensitized-solar-cells-based-zno-bifunctional-001532nas a2200253 4500008004100000022001400041245012400055210006900179260007900248300001200327490000700339520059300346653002900939653002300968653001700991653001601008653002501024100001601049700001701065700002001082700002901102700001901131856012801150 2009 eng d a1388-248100aChemical bath deposition of CdS quantum dots on vertically aligned ZnO nanorods for quantum dots-sensitized solar cells0 aChemical bath deposition of CdS quantum dots on vertically align a360 PARK AVE SOUTH, NEW YORK, NY 10010-1710 USAbELSEVIER SCIENCE INCcJAN a103-1060 v113 a

Formation of US quantum dots (Q dots) on the vertically aligned ZnO nanorods electrode was carried out by chemical bath deposition. The diameter and thickness of ZnO nanorods are similar to 100-150 nm and similar to 1.6 mu m, respectively, and CdS Q dots on ZnO nanorods have a diameter of smaller than 15 nm. In application of the Q dots-sensitized solar cells, composite film exhibited a power conversion efficiency of 0.54% under air mass 1.5 condition (80 mW/cm(2)), and incident-photon-to-current conversion efficiency showed 18.6%. (c) 2008 Elsevier B.V. All rights reserved.

10aChemical bath deposition10aPhotosensitization10aquantum dots10asolar cells10aWet-chemical process1 aLee, Wonjoo1 aMin, Sun, Ki1 aDhas, Vivek, V.1 aOgale, Satishchandra, B.1 aHan, Sung-Hwan uhttps://library.ncl.res.in/content/chemical-bath-deposition-cds-quantum-dots-vertically-aligned-zno-nanorods-quantum-dots-002168nas a2200241 4500008004100000022001400041245014700055210006900202260007700271300001400348490000700362520124400369653002101613653001501634653001301649653002001662653001601682100002501698700002801723700002501751700002401776856012601800 2013 eng d a2192-650600aRedox-mediated synthesis of functionalised graphene: a strategy towards 2D multifunctional electrocatalysts for energy conversion applications0 aRedoxmediated synthesis of functionalised graphene a strategy to aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcOCT a1296-13030 v783 a

A simple, one-step synthetic route for developing a two-dimensional multifunctional electrocatalyst is reported, by the functionalisation of graphene using oxidised ethylenedioxythiophene (O-EDOT). The mutually assisted redox reaction between graphene oxide (GO) and EDOT facilitates the reduction of GO to graphene with a concomitant deposition of O-EDOT on the surface of the graphene. The oxidised surface of GO catalyses the reaction without using an added reducing agent, so a controlled and uniform deposition of O-EDOT is ensured on the surface of graphene, which essentially prevents the restacking of the layers. UV/Visible, IR, Raman and X-ray photoelectron spectroscopy give valid evidence for the reduction and functionalisation of graphene sheets. The functional groups present on the surface of graphene are found to tune the physical and chemical properties of graphene. Consequently, the functionalised material displays enhanced electrocatalytic activity for the reduction of oxygen to water and I3- to I- relative to pristine graphene. These distinct property characteristics make the material a versatile cathode electrocatalyst for both alkaline anion-exchange membrane fuel cells and dye-sensitised solar cells.

10aelectrocatalysts10afuel cells10agraphene10aredox chemistry10asolar cells1 aUnni, SreeKuttan, M.1 aBhange, Siddheshwar, N.1 aAnothumakkool, Bihag1 aKurungot, Sreekumar uhttps://library.ncl.res.in/content/redox-mediated-synthesis-functionalised-graphene-strategy-towards-2d-multifunctional-002295nas a2200217 4500008004100000022001400041245016500055210006900220260000800289300001100297490000800308520148300316653003001799653002501829653002301854653001601877100001501893700001801908700002201926856012901948 2020 eng d a0925-838800aInvestigating effect of strain on electronic and optical properties of lead free double perovskite Cs2AgInCl6 solar cell compound: A first principle calculation0 aInvestigating effect of strain on electronic and optical propert cMAR a1527580 v8173 a

Despite serious problems associated with toxicity of lead, lead halide perovskite based solar cells have resulted with remarkable efficiency and hence gained much interest. To overcome this aspect, numerous solutions are attempted by researchers which include the development of new environmental friendly lead free double perovskite (DP) photovoltaic materials. Enlightening on the same line, we report first principle calculations on electronic and optical properties of Cs2AgInCl6 solar photovoltaic materials. Present opto-electronic computations for lead free DP compound, have been performed using the full potential linearized augmented plane wave method. In present investigations, we have adopted exchange and correlation potentials prescribed by Perdew et al. and the most accurate Tran-Blaha modified Becke-Johnson. Both exchange and correlation potential computations are performed with and without spin orbit coupling. Results obtained for electronic and optical properties are validated by systematic comparison with available experimental data. Reasonable reconciliation between investigated results and the available experimental data, endorse accuracy of present computations. To identify the effect of strain on energy gap and hence on the optical properties of Cs2AgInCl6 compound, computations of electronic and optical properties have also been performed under the different values of strain application. (C) 2019 Elsevier B.V. All rights reserved.

10aDensity functional theory10aElectronic Structure10aOptical properties10asolar cells1 aSoni, Amit1 aBhamu, K., C.1 aSahariya, Jagrati uhttps://library.ncl.res.in/content/investigating-effect-strain-electronic-and-optical-properties-lead-free-double-perovskite02244nas a2200229 4500008004100000022001400041245008800055210006900143260000800212300001400220490000600234520150700240653001901747653001601766653001601782653002401798653001601822100001901838700002101857700001901878856011701897 2020 eng d a2574-096200aReduction of trap and polydispersity in mutually passivated quantum dot solar cells0 aReduction of trap and polydispersity in mutually passivated quan cSEP a8903-89110 v33 a

Control over surface passivation is a key to manage the optoelectronic properties in low-dimensional nanomaterials because of their high surface-to-volume ratios. Tunable band gap quantum dots (QDs) are a potential building block for the development of optoelectronic devices like solar cells, photodetectors, and light-emitting diodes. Long and insulating surface ligands of colloidally synthesized QDs are exchanged by short ligands to attain compact arrangement in thin films to facilitate the charge transport process. However, the ligand exchange process often resulted in reduced surface passivation, inhomogeneous QD fusion, and deterioration of energy band gap, which adversely impact their performance in solar cells. Here, we introduce a surface passivation strategy where the QDs are mutually passivated by the organic ligand 3-methyl mercapto propionate and inorganic halometallate ligands to develop a conducting QD ink. The mutually passivated QDs (MPQDs) show significant improvement in optoelectronic properties in maintaining the trap-free energy band gap and size monodispersity. The photovoltaic performance of MPQDs shows a 33% average increase in power conversion efficiency (PCE) over the conventional halometallate passivation to attain 9.6% PCE in MPQD solar cells. The improvements in photovoltaic parameters are corroborated by the reduction in density of the intermediate trap states and an increase in depletion width and diffusion length in MPQD-based solar cells.

10apolydispersity10aquantum dot10asolar cells10asurface passivation10atrap states1 aSharma, Ashish1 aMahajan, Chandan1 aRath, Arup, K. uhttps://library.ncl.res.in/content/reduction-trap-and-polydispersity-mutually-passivated-quantum-dot-solar-cells02680nas a2200241 4500008004100000022001400041245009400055210006900149260000900218300001600227490000700243520189100250653002202141653001902163653001602182653001602198653002402214653001602238100002102254700001902275700001902294856012502313 2020 eng d a1944-824400aSolution-phase hybrid passivation for efficient infrared-band gap quantum dot solar cells0 aSolutionphase hybrid passivation for efficient infraredband gap  cNOV  a49840-498480 v123 a

The broad tunability of the energy band gap through size control makes colloidal quantum dots (QDs) promising for the development of photovoltaic devices. Large-size lead sulfide (PbS) QDs, exhibiting a narrow energy band gap, are particularly interesting as they can be used to augment perovskite and c-Si solar cells due to their complementary NIR absorption. However, their complex surface chemistry makes them difficult to process for the development of solar cells. The shape of the QDs transformed from octahedron to cuboctahedron as their size increases, a phenomenon guided by surface energy minimization. As a result, the surface properties change drastically for large-size QDs, which exhibit nonpolar (200) facets and polar (111) facets, as opposed to only (111) facets in small-size QDs. Recent advancements in solution-phase surface passivation strategies, used for the development of high-performance solar cells using the small size and wide band gap QDs, failed to translate a similar enhancement in the case of large-size and narrow band gap QDs. Here, we report a hybrid passivation strategy for large-size and narrow band gap QDs to passivate both (111) and (200) facets, respectively, using inorganic lead triiodide (PbI3-) and organic 3-chloro-1-propanethiol (CPT). By employing charge balance calculation, we identified the desired narrow band gap for QDs to complement the perovskite and c-Si absorption. The distinct choice of the organic ligand CPT enhances the colloidal stability of QDs in the solution phase and improves surface passivation to stop QD fusion in solid films. Photophysical properties show narrower excitonic and emission peaks and a reduction in the Stokes shift. Hybrid passivation leads to a 94% increase in the power conversion efficiency of solar cells and a 74% increase in the external quantum efficiency at the excitonic peak.

10ainfrared band gap10apolydispersity10aquantum dot10asolar cells10asurface passivation10atrap states1 aMahajan, Chandan1 aSharma, Ashish1 aRath, Arup, K. uhttps://library.ncl.res.in/content/solution-phase-hybrid-passivation-efficient-infrared-band-gap-quantum-dot-solar-cells02718nas a2200265 4500008004100000022001400041245008000055210006900135260000800204300001400212490000600226520192400232653001502156653001102171653001902182653001602201653001602217653001402233100001902247700001902266700001802285700001902303700001902322856011102341 2021 eng d a2574-097000aCrack-free conjugated PbS quantum dot-hole transport layers for solar cells0 aCrackfree conjugated PbS quantum dothole transport layers for so cAPR a4016-40250 v43 a

Colloidal quantum dots (QDs) benefit from solution-phase processing and band-gap tuning for their application in solar cell development. Today's QD solar cells rely on solid-state ligand exchange (SLE) to replace bulky oleic acid (OA) ligands with small 1,2-ethanedithiol (EDT) ligands to develop a conducting hole transport layer (HTL). High volume contraction in EDT conjugated QD films, however, leads to crack and porosity in the HTL, which is a major cause of concern for the device reproducibility and large-area solar cell development. We show that partial removal of the OA ligands in the solution phase reduces the volume contraction in solid films, thereby allowing the growth of crack-free QD films in the SLE process. The cleaning of QDs by repeated precipitation and redispersion using a protic methanol (MeOH) solvent helps with partial removal of the OA ligands, but it is detrimental to the electronic properties of QDs. We develop a one-step solution-phase partial ligand-exchange process using ammonium salts, which enable partial replacement of the OA ligands and passivation of the QD surface. Introduction of the facile partial ligand-exchange process eliminates the need for tedious and wasteful multiple cleaning steps with MeOH, while improving the photophysical properties of QDs. The advancement in QD processing helps to build crack-free, smooth, and conjugated QD films for their deployment as HTLs in solar cell development. Partial ligand exchange with NH4SCN leads to a 1.5 times increase in p doping and mobility over multiple MeOH-cleaned PbS QD films. HTLs developed using NH4SCN QDs show an improved photovoltaic performance to attain a 10.5% power conversion efficiency. Improvement in the depletion width and hole collection efficiency leads to a superior photovoltaic performance, as confirmed from experimental studies and one-dimensional solar cell capacitance simulation.

10aEfficiency10aligand10apolydispersity10aquantum dot10asolar cells10athin film1 aSharma, Ashish1 aDambhare, Neha1 aBera, Jayanta1 aSahu, Satyajit1 aRath, Arup, K. uhttps://library.ncl.res.in/content/crack-free-conjugated-pbs-quantum-dot-hole-transport-layers-solar-cells01963nas a2200241 4500008004100000022001400041245012400055210006900179260000800248300001200256490000700268520114900275653002301424653001101447653001701458653001601475653003001491100001901521700001901540700002101559700001901580856012201599 2022 eng d a2194-428800aThiocyanate- and thiol-functionalized p-doped quantum dot colloids for the development of bulk homojunction solar cells0 aThiocyanate and thiolfunctionalized pdoped quantum dot colloids  cSEP a22004550 v103 a

Progress in device engineering and surface passivation strategies has led to steady progress in colloidal quantum dot (QD) solar cells. Bulk homojunction (BHJ) device architecture has several advantages over the conventional planar junction in developing QD solar cells. Herein, surface ligand chemistry is utilized to control the doping type and dispersibility of oppositely doped PbS QDs to develop BHJ solar cells. Thiocyanate and thiol ligand combination is introduced to develop p-PbS QD ink, which is blended with halide-passivated n-PbS QDs to build BHJ solar cells. It is shown that BHJ solar cells are benefited from high energy offset and higher hole mobility. This leads to the superior carrier extraction from a thicker active layer without compromising fill factor and open circuit voltage. Power conversion efficiency has reached 10.7% in 530 nm-thick BHJ solar cells, a 24% improvement over the best performing planar solar cells. With the help of the 1D solar cell capacitance simulator, it is shown that a 15% efficient QD solar cell can be realized by further improving the hole mobility above 0.1 cm(2) V-1 s(-1).

10abulk homojunctions10aDoping10aquantum dots10asolar cells10asurface functionalization1 aDambhare, Neha1 aSharma, Ashish1 aMahajan, Chandan1 aRath, Arup, K. uhttps://library.ncl.res.in/content/thiocyanate-and-thiol-functionalized-p-doped-quantum-dot-colloids-development-bulk02123nas a2200265 4500008004100000022001400041245007200055210006900127260000800196490000700204520129400211653002501505653001801530653001801548653001701566653001601583653002401599100002101623700002301644700002001667700001901687700002901706700001901735856010301754 2023 eng d a2194-428800aMulti-bandgap quantum dots ensemble for near-infrared photovoltaics0 aMultibandgap quantum dots ensemble for nearinfrared photovoltaic cJUN0 v113 a

Narrow bandgap quantum dots (QDs) are an important class of materials for near-infrared (NIR) optoelectronic devices owing to their size-tunable bandgap and chemical root processing. In photovoltaic applications, NIR QDs could be particularly useful to complement the sub-bandgap transmission loss of NIR solar radiation from perovskite and c-Si solar cells. However, insufficient carrier extraction thickness associated with the narrow NIR excitonic bandwidth of QDs limits the conversion efficacy of the broad NIR solar spectrum. Here, we utilize a multi-bandgap QD ensemble which widens the NIR absorption bandwidth to mimic the broad solar spectrum. A solution-phase ligand passivation strategy is used to control doping properties and energy level alignment of multi-bandgap QDs. We successfully developed bulk-heterojunction solar cells using the multi-bandgap QD ensemble, which yields higher carrier extraction thickness and broader NIR absorption. The gain from NIR absorption and carrier transport resulted in higher short-circuit current generation and power conversion efficiency (PCE) in solar cell devices. The champion device shows 8.73% PCE under 1.5 AM solar illumination and 7.44% and 5.05% PCE for the NIR photons transmitted from perovskite and c-Si layers.

10abulk-heterojunctions10amulti-bandgap10anear-infrared10aquantum dots10asolar cells10asurface passivation1 aMahajan, Chandan1 aDambhare, Neha, V.1 aBiswas, Arindam1 aSharma, Anjali1 aShinde, Dipak, Dattatray1 aRath, Arup, K. uhttps://library.ncl.res.in/content/multi-bandgap-quantum-dots-ensemble-near-infrared-photovoltaics