Colloidal quantum dots (QDs) stand among the most attractive light-harvesting materials to be exploited for solution-processed optoelectronic applications. To this aim, quantitative replacement of bulky electrically insulating ligands at QD surface coming from synthetic procedure is mandatory. Here we present a conceptually novel approach design nanomaterials demonstrating that modification with suitable short conjugated organic molecules permits us drastically enhance light absorption QDs,...

Phenothiazine-based compounds, PTZ1 and PTZ2, were synthesized through straightforward Buchwald–Hartwig Suzuki–Miyaura cross-couplings, respectively, by binding the suitable donor groups (diarylamine or triarylamine) to a phenothiazine core. structures proven for first time as hole-transporting materials in solution-processed lead trihalide perovskite-based solar cells. A dramatic effect exerted presence of phenylene spacers was observed on relevant photovoltaic performances. The power...

The surface passivation by organic ligands of differently composed cesium lead halide perovskite nanocrystals was explored.

CsPbBr

Due to a still limited understanding of the reasons making 2,2′,7,7′-tetrakis(N,N-di-p-methoxyphenylamine)-9,9′-spirobifluorene (Spiro-OMeTAD) state-of-the-art hole-transporting material (HTM) for emerging photovoltaic applications, molecular tailoring organic components perovskite solar cells (PSCs) lacks in solid design criteria. Charge delocalization radical cationic states can undoubtedly be considered as one essential prerequisites an HTM, but this aspect has been investigated...

Abstract Two new hole selective materials (HSMs) based on dangling methylsulfanyl groups connected to the C‐9 position of fluorene core are synthesized and applied in perovskite solar cells. Being structurally similar a half Spiro‐OMeTAD molecule, these HSMs (referred as FS DFS) share redox potentials but endowed with slightly higher mobility, due planarity large extension their structure. Competitive power conversion efficiency (up 18.6%) is achieved by using suitable Time‐resolved...

Abstract Colloidal quantum dots are composed of nanometer‐sized crystallites inorganic semiconductor materials bearing organic molecules at their surface. The organic/inorganic interface markedly affects forms and functions the dots, therefore its description control important for effective application. Herein we demonstrate that archetypal colloidal PbS adapt to surroundings, thus existing in solution phase as equilibrium mixtures with (metal‐)organic ligand core components. interfacial...

A tetracoordinated redox couple, made by [Cu(2-mesityl-4,7-dimethyl-1,10-phenanthroline)2][PF6], 1, and its Cu(II) form [Cu(2-mesityl-4,7-dimethyl-1,10-phenanthroline)2][PF6]2, 2, has been synthesized, electrochemical photochemical features have investigated compared with those of a previously published Cu2+/Cu+ shuttle, namely, [Cu(2,9-dimethyl-1,10-phenanthroline)2][PF6], 3, pentacoordinated oxidized [Cu(2,9-dimethyl-1,10-phenanthroline)2Cl][PF6], 4. The detrimental effect the fifth Cl–...

This study aims at rationalizing the effects of lead/surfactant ratio on structural evolution cesium lead-bromide perovskite nanocrystals (NCs), ascertaining how their shape and surface composition can be modulated by suitably adjusting ligand amount (an equivolumetric mixture oleic acid oleyl amine) relatively to lead bromide. The tailoring reaction conditions allows obtainment blue-emitting CsPbBr3 nanoplatelets in presence excess, while green-emitting nanocubes are achieved under...

This study deals with an investigation of the spectral stability differently structured polyfluorenes (PFs), deprived 9-H defects, embodying 9,9-dialkylfluorene (P1), 9,9-diarylfluorene (P2), or 9,9-diarylfluorene/9,9-dibenzylfluorene units in a 1:1 alternating fashion (P3). Thermal annealing UV irradiation carried out on films P1–P3 air revealed that their typical blue photoluminescence is invariably stained, independently 9-substitution, by appearance low-energy band (g-band) pointing...

The synthesis of a novel and efficient π-extended D-A-π-A organic sensitizer (G3, η = 8.64%) for dye-sensitized solar cells has been accomplished by applying the green chemistry pillars, aiming at overriding traditional routes involving organometallic intermediates with innovative synthetic strategies reducing waste burden dye production costs. It demonstrated that obtainment complex target can be exclusively pursued via direct arylation reactions. Green metrics comparison those pathway...

New compounds based on heptazine core bearing phenoxazines substituent were synthesized, starting from the easily accessible 2,5,8-tri(3,5-diethyl-1H-pyrazolyl-1-yl)heptazine. The pyrazolyl groups substituted by one, two, or three phenoxazines, yielding H1, H2, H3. Heptazine (Hz) being an exceptionally strong electron acceptor and donors, these novel are expected to exhibit low-lying singlet triplet states of pronounced charge-transfer (CT) character. excited-state electronic structures...

Eleven years after the first reports on intramolecular catalyst transfer polycondensations, this review aims to critically recap fundamental “lessons” that can be learned from historic literature as well fervid activity has emerged in last three years.

The chemical species (ligands) at the surface of colloidal inorganic semiconductor nanocrystals (QDs) mediate their interactions with surroundings. solvation QDs reflects a subtle interplay between ligand-solvent and ligand-ligand interactions, which eventually compete coordination ligands QD surface. are indeed fundamental to preserve optoelectronic properties foster effective application QD-based inks nanocomposites. Here we investigate such ligand by exploiting diffusion ordered NMR...

Lead halide perovskite nanocrystals (NCs) are particularly suitable for light-emitting and photocatalysis applications, where their potential can be maximized by controlling the surface composition of organic shell. In this study, preparation CsPbClxBr3–x NCs at room temperature in toluene is described. Three differently structured surfactants utilized synthesis, each with a specific function, namely, solubilization lead precursor (n-Hept4NBr), passivation modification...

Abstract The causes of the spectral instability poly[9,9‐dioctylfluoren‐2,7‐diyl‐co‐2′,7′‐spiro(cyclohexane‐1,9′‐fluorene)] during thermal annealing in air, which leads to a green photoluminescence (PL) emission band, are investigated. I / blue ratio evolution ( = intensity) is found be independent amount monoalkylfluorene defects, despite fact that their presence might regarded as trigger for radical process leading polymer degradation trace metal catalyst. Furthermore, absence correlation...

A photovoltachromic window can potentially act as a smart glass skin which generates electric energy common dye-sensitized solar cell and, at the same time, control incoming flux by reacting to even small modifications in radiation intensity. We report here successful implementation of novel architecture based on an engineered bifunctional counter electrode consisting two physically separated platinum and tungsten oxide regions, are arranged form complementary comb-like patterns. Solar light...

Two simple small molecules are designed and successfully implemented here as hole-transporting material (HTM) in perovskite-based solar cells (PSCs). With the aim of elucidating interconnection between molecular structure, properties, their role working devices, these HTMs both thin planar direct (n–i–p) inverse (p–i–n) geometries. It is observed how HTM layer morphology influences photovoltaic performance. Moreover, from analysis different fundamental information retrieved on factors...

The stability of perovskite solar cells (PSCs) is greatly affected by the interface between active layer and hole transport material (HTM). rational design HTMs with effective anchoring to surface an emerging elegant strategy promote compact ordered interfaces that lead highly efficient stable PSCs. Herein, we propose two fluorene-based HTM molecular architectures (SCF1 SCF2) derived from popular yet expensive Spiro-OMeTAD. Their employment as dopant-free in standard triple-cation CsFAMA...

A practical synthesis for 9,10-bis(alkoxyphenyl)-2,7-diiodophenanthrenes is described. 9,10-Bis(4-hexyloxyphenyl)-2,7-diiodophenanthrene was selectively obtained by a one-pot reaction of 10,10-bis-(4-hexyloxy-phenyl)-2,7-diiodo-10H-phenanthren-9-one with 1 equiv triethylsilane in trifluoroacetic acid. The target molecular architecture demonstrated to be useful precursor obtaining the corresponding poly(phenanthrene) and poly(phenanthrylene-vinylene).

The initiation of the Suzuki cross-coupling polymerisation with a fluorene-based AB-type monomer was finely tuned within chain-growth regime by suitable control species generated Pd(AcO)2/t-Bu3P/K3PO4 catalytic system. prototypical poly(9,9-di-n-octyl-fluorene) obtained extremely fast (1 min) rates, excellent polydispersities (1.16) and molecular weights dependent on monomer/catalyst molar ratio, without need to resort formal chain-initiators.