Semitransparent Perovskite Solar Cells for Building Integrated Photovoltaics: Recent Advances

Perovskite solar cells technology is one of the most advanced and fascinating technologies in the field of photovoltaics due to its low-cost processing and delivering efficient power conversion efficiencies. The ability to become transparent is another prolific property of the perovskite solar cells, which this property has been tried to be exploited in recent times by researchers to serve the environmental and energy needs of human beings. Using this transparency and enabling semitransparent perovskite solar cells (ST-PSCs) to be placed on the windows and rooftops of buildings will reduce room temperature along with fulfilling certain requirements of power needs. This review pays attention to the recent developments in the semitransparent perovskite solar cells from the perspective of the structure of ST PSCs, electrodes and others

Synthesis and photo electrochemical characterization of an extended π-conjugated heteroleptic ruthenium (II) complex

A new extended π-conjugate heteroleptic ruthenium(II) complex (m-HRD-1) that contains a 4,4'-bis-2-(5(3,5-di-tert-butylphenyl)thiophene-2-yl)vinyl)2,2'-bipyridine as ancillary ligand, 4,4’-dicaboxy-2,2'-bipyridine as anchoring group, and two thiocyanate ligands in its molecular structure have been designed, synthesized and characterized by CHN, Mass, 1H-NMR, UV-Vis, and fluorescence spectroscopies as well as cyclic voltammetry. Electrochemical and theoretical studies showed that the LUMO of the sensitizer is above TiO2 conduction band and the HOMO is below the redox potential of the electrolyte. This new sensitizer was tested in dye-sensitized solar cells using liquid redox couple (I-/I3-) and its performance was compared to the standard sensitizer N719

Near-infrared absorbing unsymmetrical Zn(II) phthalocyanine for dye-sensitized solar cells

Unsymmetrical Zn phthalocyanine consisting of six S-aryl groups at α-positions and a carboxy anchoring group at β-position has been designed and synthesized for dye-sensitized solar cells (DSCs) applications. The unsymmetrical phthalocyanine has been characterized by elemental, MALDI-MS, IR, 1H NMR, UV–Vis, fluorescence (steady-state & lifetime) and electrochemical (including spectroelectrochemical) methods. The Q-band absorption maxima of the unsymmetrical phthalocyanine was red-shifted due to the presence of S-aryl groups, which destabilizes the HOMO level consistent with electrochemical and in situ spectroelectrochemical studies. The redox processes are assigned to the macrocyclic ring-based electron transfer processes, the LUMO of the unsymmetrical phthalocyanines lies above the TiO2 conduction band, and the HOMO is well below the potential of the I−/I3− redox electrolyte. The experimental results are supported by DFT/TD-DFT studies. The new unsymmetrical phthalocyanines was tested in DSCs using I−/I3− redox electrolyte system

Dye sensitization of a large band gap semiconductor by an iron(III) complex

The Fe(III) complex, [FeIII(HQS)3] (HQS = 8 hydroxyquinoline-5-sulfonic acid), is found to effect sensitization of the large band gap semiconductor, TiO2. The role of interfacial electron transfer in sensitization of TiO2 nanoparticles by surface adsorbed [FeIII(HQS)3] was studied using femtosecond time scale transient absorption spectroscopy. Electron injection has been confirmed by direct detection of the electron in the conduction band. A TiO2-based dye-sensitized solar cell (DSSC) was fabricated using [FeIII(HQS)3] as a sensitizer, and the resulting DSSC exhibited an open-circuit voltage value of 425 mV. The value of the short-circuit photocurrent was found to be 2.5 mA/cm2. The solar to electric power conversion efficiency of the [FeIII(HQS)3] sensitized TiO2-based DSSC device was 0.75 %. The results are discussed in the context of sensitization of TiO2 by other Fe(II)-dye complexes

Novel catalytic Hunsdiecker-Heck (CHH) strategy toward all-E stereocontrolled ferrocene-capped conjugated push-pull polyenes

Halodecarboxylation reaction of ferrocenylacrylic acid 1 and ferrocenyldienoic acid 3d with N-bromo- and N-iodosuccinimide in the presence of catalytic tetrabutylammonium trifluoroacetate at &#8722;40&#176;C and &#8722;78&#176;C affords the corresponding &#946;-halovinylferrocenes 2a, 2b and &#948;-haloferrocenyldiene 4 in 37-72% yields. Heck reaction of &#946;-iodovinylferrocene 2a with vinyl substrates (CH<SUB>2</SUB>=CH-Z where Z=CO<SUB>2</SUB>Me, CO<SUB>2</SUB>Et, COMe, CO<SUB>2</SUB>H, CONH<SUB>2</SUB>, 4'-NO<SUB>2</SUB>C<SUB>6</SUB>H<SUB>4</SUB>) in the presence of tri(4-tolyl)arsine/palladium acetate/lithium chloride/triethylamine in acetonitrile at 35-80&#176;C affords the corresponding ferrocenyldienes 3a-3f in 50-81% isolated yields. Similar reaction of &#948;-iodoferrocenyldiene 4 with vinyl substrates (CH<SUB>2</SUB>=CH-Z where Z=CO<SUB>2</SUB>Me, CO<SUB>2</SUB>Et, CO<SUB>2</SUB>H, 4'-NO<SUB>2</SUB>C<SUB>6</SUB>H<SUB>4</SUB>) affords the corresponding ferrocenyltrienes 5a-5d in 55-87% isolated yields. The ferrocene-capped conjugated dienes and trienes show excellent all-E stereoselectivity (vide NMR). The electronic, redox, and nonlinear optical properties of ferrocenylpolyenes have been evaluated. The data suggest that upon increasing the polyene chain length, (a) the absorption maxima shifts progressively to higher wavelength, (b) the oxidation potential of the Fc/Fc<SUP>+</SUP> couple (E<SUB>&#189;</SUB>) decreases, and (c) the HRS-derived second-order NLO response (&#946;) increases. From the insights derived from semiempirical calculation (ZINDO/1), a mechanism for the halodecarboxylation reaction has been proposed suggesting the prior formation of tetrabutylammonium salt of ferrocenylacrylic acid I. Attack of the halogenium atom at the &#960;<SUB>C=C</SUB> in I leads to the formation of intermediate II, and the latter triggers the elimination of carbon dioxide

Synthesis and photo electrochemical characterization of an extended π-conjugated heteroleptic ruthenium (II) complex

A new extended π-conjugate heteroleptic ruthenium(II) complex (m-HRD-1) that contains a 4,4'-bis-2-(5(3,5-di-tert-butylphenyl)thiophene-2-yl)vinyl)2,2'-bipyridine as ancillary ligand, 4,4’-dicaboxy-2,2'-bipyridine as anchoring group, and two thiocyanate ligands in its molecular structure have been designed, synthesized and characterized by CHN, Mass, 1H-NMR, UV-Vis, and fluorescence spectroscopies as well as cyclic voltammetry. Electrochemical and theoretical studies showed that the LUMO of the sensitizer is above TiO2 conduction band and the HOMO is below the redox potential of the electrolyte. This new sensitizer was tested in dye-sensitized solar cells using liquid redox couple (I-/I3-) and its performance was compared to the standard sensitizer N719