High Efficiency Si Solar Cells Characterization Using

Abstract. Impedance Spectroscopy has been used to analyse commercial Si photovoltaic solar cells, to obtain information about minority carrier lifetimes, series and parallel resistances, and acceptor impurity densities. Silicon solar cells efficiencies ranging between 17 and 18% from different manufacturers have been analysed obtaining differences mainly in the electron lifetimes and doping densities. Relations between these parameters and DC curves are discussedMinisterio de Economía y Competitividad under project TEC2013-4835-

[Pt]2Pb Trinuclear Systems: Impact of the Anionic Platinum Fragment on the Lead Environment and Photoluminescence

A comparison of the solid structures of three novel trinuclear sandwich R2Pb systems (NBu4)2[{Pt(CCTol) 4}2Pb(OH2)2] 1, [{Pt(bzq) (CCPh)2}2Pb] 2, and (NBu4)[{Pt(bzq) (CCC6H4-CF3-4)2} 2Pb(O2ClO2)] 4 (NBu4[3· (O2ClO2)]) with that of the previously reported (NBu 4)2[{Pt(C6F5)4} 2Pb] 5 showed that the local environment of PbII is highly sensitive to the nature of the anionic platinate(II) precursors. The photoluminescence (PL) studies of all 1-5 complexes revealed a dependence of PL on the structure type. Thus, complexes 1 and 5 exhibit metal centered emissions (1, 497 nm, 77 K; 5, 539 nm, ø = 0.43, 298 K) related to the linear (5) or bent (1 Pt-Pb-Pt 149.9°) trinuclear entities. However, in complexes 2-4, that have unprecedented PbII1(CCR) bonding interactions and very short PtPb and PtPt distances, the emissive state in solid state (77 K) is attributed to a 3MLM'CT [Pt(1)(CCR)Pt(2)/Pb(sp)*(CCR)] state mixed with some * excimeric character in neutral complexes 2 (R = Ph) and 3 (R = C6H4-CF3-4), and in the case of the adduct (NBu4)[{Pt(bzq)(CCC6H4-CF 3-4)2}2Pb(O2ClO2)] 4 modified also by PbIIO (O2ClO2 -) contacts. © 2008 American Chemical Society

A rapidly-reversible absorptive and emissive vapochromic Pt(II) pincer-based chemical sensor

Selective, robust and cost-effective chemical sensors for detecting small volatile-organic compounds (VOCs) have widespread applications in industry, healthcare and environmental monitoring. Here we design a Pt(II) pincer-type material with selective absorptive and emissive responses to methanol and water. The yellow anhydrous form converts reversibly on a subsecond timescale to a red hydrate in the presence of parts-per-thousand levels of atmospheric water vapour. Exposure to methanol induces a similarly-rapid and reversible colour change to a blue methanol solvate. Stable smart coatings on glass demonstrate robust switching over 104 cycles, and flexible microporous polymer membranes incorporating microcrystals of the complex show identical vapochromic behaviour. The rapid vapochromic response can be rationalised from the crystal structure, and in combination with quantum-chemical modelling, we provide a complete microscopic picture of the switching mechanism. We discuss how this multiscale design approach can be used to obtain new compounds with tailored VOC selectivity and spectral responses

Generation of (mu-Ethynediyl)(methylalkoxycarbene)diplatinum Complexes from Reaction of cis,trans-[(CO)(C6F5)2Pt(mu-eta2-C=CSiMe3)Pt(=CSiMe3)L2] with ROH (R = Et, Me)

Reaction of cis-[Pt(C6F5)2(CO)(THF)] with trans-[Pt(CCSiMe3)2L2], followed by reaction of the neutral -2-monoacetylide-bridged diplatinum intermediates cis,trans-[(OC)(C6F5)2-Pt(- 2-CCSiMe3)Pt(CxbaCSiMe3)L 2] (L = PPh3 (1), PEt3 (2)) with alcohols (EtOH, MeOH) yields the (-ethynediyl)(methylalkoxycarbene)diplatinum species cis,trans-[(OC)(C6F5) 2-Pt-CC-Pt{C(Me)OR}L2] (L = PPh3, R = Et (3a), Me (3b); L = PEt3, R = Et (4a), Me (4b)), resulting from unexpected rearrangement chemistry involving bridging and terminal (trimethylsilyl)acetylide ligands. The X-ray molecular structure of the complex cis,trans-[(OC)(C6F5) 2Pt-CC-Pt{C(Me)OEt}(PEt3)2] (4a) has been determined. It crystallizes in the monoclinic system, space group P21/c with a = 15.216(3) Å, b = 14.197(4) Å, c = 18.167(5) Å, = 107.99(2)°, V = 3733(2) Å3, and Z = 4. The two coordination planes around the platinum atoms adopt an almost eclipsed arrangement (dihedral angle 6.7°) rather than the staggered form found in similar diplatinum complexes. © 1995 American Chemical Society

Synthesis and characterization of mono and heteropolynuclear luminescent alkynyl platinum diphenylphosphinous acid/phosphinite complexes

The novel anionic mononuclear cis-bis(alkynyl) platinum complexes with a chelated diphenylphosphinous acid/diphenylphosphinite (NBu4)[cis-Pt(C6;CR)2{(PPh2O) 2H}] (R=But 1a, Ph 1b) have been prepared by treatment of [cis-Pt(C6;CR)2COD] with PPh2(O)H and (NBu4)(acac) in a 1:2:1 molar ratio. The molecular structure of 1a has been determined by single-crystal X-ray diffraction. Neutralization reactions of complexes 1 with 1 equiv. of AgClO4 or CuTfO (TfO=triflate) produce tetranuclear dimetallic complexes [cis-Pt{(PPh2O)2H}(-C :2-CCR)2M]2 (M=Ag, 2a, 2b; M=Cu 3a, 3b), in which each anionic fragment {Pt}(CCR)2- ({Pt}=Pt{(PPh2O)2H}) acts as a -2:2 bridging ligand towards two different silver(I) or copper(I) centres. Finally, the reactions of (NBu4){Pt}(CCR)2 1 with [CuCl]n produce heterodinuclear platinum(II)-copper(I) complexes (NBu4)[cis-Pt{(PPh2O)2H}(-C :2-CCR)2CuCl] (4a, 4b), in which both alkyne units are 2-coordinated side-on to the copper(I) chloride. All complexes are emissive in frozen CH2Cl2 solutions. © 2002 Elsevier Science B.V. All rights reserved

Discrete Triangle, Square and Hexametallic Alkynyl Cyano-Bridged Compounds Based on [cis-Pt(C=CR)2(CN)2]2- Building Blocks

Novel mixed bis(alkynyl)-bis(cyano)platinate(II) species [cis-Pt(CCR2(CN)2]2- (1a: R = tBu, 1b: R = Ph) have been prepared and their potential as building blocks in the generation of self-organized systems with a variable molecular architecture has been studied. The reaction of 1 with the ditopic acceptor species [{cis-Pt(C6F5)2S}2(dppa)] (dppa = diphenyl-phosphinoacetylene) gave the dianionic cyanide/dppa bridged molecular platinotriangles (NBu4)2[(C6F5) 2Pt(-dppa){(-CN)2Pt(CCR) 2}Pt(C6F5)2] (2). X-ray analysis of 2a confirmed that the "Pt2(C6F5) 4(-dppa)" binuclear moiety is connected to the dianionic "Pt(CCR)2(CN)2" unit by two bridging cyanide ligands. Moreover, treatment of 1 with the solvent cationic species [M(cod)(acetone)2]+ afforded heterometallic molecular squares Pt2M2 (M = Rh, Ir) containing cyanide bridges and terminal alkynyl ligands, (NBu4)2[cyclo{[cis-Pt(CCR) 2(-CN)2][M(cod)]}2] (3: M=Rh, 4: M = Ir). The solid-state structures of phenyl derivatives have been determined by X-ray crystallography. The terminal alkynyl ligands in these cyanide-bridged molecular squares 3 and 4, have been used in the assembly of higher multimetallic complexes. Thus, very unusual bis(double-alkynide) -cyanide-bridged hexametallic compounds (NBu4)2[{(C6F 5)2Pt (-C CPh)2(-CN) 2}2{M(cod)}2] (5b: M = Rh, 6b: M = Ir) were easily formed by simple reactions of 3b and 4b with two equivalents of [cis-Pt(C 6F5)2(thf)2]. An X-ray diffraction study on complex 5b indicated that the derivative was formed by a simultaneous migration of one -alkynyl group from each "Pt(C CPh) 2(-CN)2" corner of the square to both "Pt(C6F5)2" units, resulting in bent ,-double-alkynyl bridging systems. Finally, the novel supramolecular anionic assemblies (NBu4)4[cyclo{[cis-Pt(CCR) 2(-CN)2][SnPh3]}4] 7 have been obtained by self-assembly of 1 and [SnPh3(acetone)2] +

Synthesis, characterisation and NMR study of paramagnetic heteropolinuclear anionic Pt-Co species. Crystal structures of [NBu4]2[{cis-Pt(C6F5)2(C=CSiMe3)2}CoCl2]·0.5(CH3)2CO and [NBu4]2[{Pt(CºCtBu)4}{CoCl2}2].1.5(CH3)2CO

The reactions of [NBu4]2[cis-Pt(C6F5) 2(CCR)2] (R=tBu or SiMe3) with CoCl2·6H2O in a 1:1 molar ratio yielded the paramagnetic binuclear species [NBu4]2[{cis-Pt(C6F5) 2(-CCR)2}CoCl2] (R=tBu (1a), SiMe, (1b)) in which thecobalt(II) chloride is coordinated 2-side on to both alkynyl ligands of the platinum fragment. Similar treatment of [NBu4]2[Pt(C=CR)4]·2H2O (R=tBu or SiMe3) with CoCl2·6H2O in a 1:2 molar ratio gave the corresponding trinuclear 1:2 adducts [NBu4]2[{Pt(-CCR)4}{CoCl 2}2] (2). The compounds were characterised by analytical and spectroscopic data and, in addition, the crystal structures of a representative complex of each category were determined: 1b·acetone and 2a·acetone. Surprisingly, whilst in the binuclear anion [{Pt(C6F5)2(CCSiMe3) 2}CoCl2]2- the cobalt atom is well embedded by the alkynyl fragments giving a precisely planar PtC4Co core and a very long PtCo separation (3.446(3) Å), in the trinuclear derivative [{Pt(CCtBu)4}{CoCl2}2] 2- the PtC4Co cores are hinged imposing significantly shorter PtCo distances (3.077(3) Å). © 1997 Elsevier Science S.A

Reactions of (sigma-alkynyl)platinum complexes with [Pd(eta3-C3H5)Cl]2. Synthesis of bis(eta2-alkyne)(eta3-allyl)palladium(II) complexes. Crystal and molecular structure of [cis-(PPh3)2Pt(mu-eta1:eta2-CºCtBu)2Pd(eta3-C3H5)](ClO4)

The -bis and tetraalkynyl anions [cis-Pt(C6F5)2(CCR)2] 2- and [Pt(CCR)4]2- (R = Ph, tBu, SiMe3) have been shown to be useful reagents for the formation of bis(-alkynyl) complexes via halide displacement reactions. They thus react with {[Pd(3-C3H5)Cl]2} in a 2:1 molar ratio to form anionic heterobinuclear zwitterionic Q[cis-(C6F5)2Pt(- 1:2-CCR)2Pd-( 3-C3H5)] (Q = PMePh3, R = Ph; Q = NBu4, R = tBu, SiMe3 1a-c) and (NBu4)[(RCC)2Pt-(-1: 2-CCR)2Pd(3-C3H 5)] (R = Ph, tBu, SiMe3 2a-c) complexes. The corresponding trinuclear 1:2 neutral adducts {[Pt(CCR)4][Pd(3-C3H 5)]2) (R = Ph, tBu, SiMe3 3a-c) were formed by the addition of 1 equiv of the tetraalkynyl anions to {[Pd(3-C3H5)Cl]2}. Binuclear derivative analogue [(PPh3)2Pt(-1: 2-CCR)Pd(3-C3H 5)](ClO4) (R = Ph, tBu 4a,b) were produced by the reaction of {[Pd(3-C3H5)Cl]2} with neutral [cis-Pt(PPh3)2(CCR)2] (1:2 ratio) in the presence of NaClO4 (excess). The heterobimetallic anionic 1c (R = SiMe3) and cationic 4b (R = tBu) complexes were characterized by X-ray diffraction. In both, the two bridging alkynyl ligands remained bonded to the platinum center and 2 coordinated to the palladium one

Synthesis of novel platinum-silver and platinum-copper complexes with bridging alkynyl ligands

The study of the reactivity of [Pt2M4(CCR)8] (MAg or cu; RPh or tBu) towards different neutral and anionic ligands is reported. This study reveals that reactions of the phenylacetylide derivatives [Pt2M4(CCPh)8] with anionic, X- (XCl or Br) or neutral donors (CNtBu or py) in a molar ratio 1:4 (m/donor ratio 1:1) yield the trinuclear anionic (NBu4)2[{Pt(CCPh)4 (MX)2] (MAg or Cu, X Cl or Br) or neutral [{Pt(CCPh04=sAGL)2] (LCNtBu or py) complexes, respectively. The crystal structure of (NBu4)2[{Pt(CCPh)4}(CuBr)2](4) shows that the anion is formed by a dianionic Pt(CCPh)4 fragment and two neutral CuBr units joined through bridging alkynyl ligands. All the alkynyl groups are bonded to Pt and 2-coordinated to a Cu atom which have an approximately trigonal-planar geometry. By contrast, similar reactions with [Pt2M4(CCtBu)8] (molar ratio M/donor 1:1) afford hexanuclear dianionic (NBu4)2[Pt2M4(CCtBu)8X2] or neutral [Pt2Ag4(CCtBu08Py2]. Only by treatment with a large exces of Br - (molar ratio M/Br- 1:2) are the trinuclear complexes (NBu4)2[{Pt(CCtBu4 (MBr)2] (MAg, Cu) obtained. Attempted preparations of analogous complexes with phosphines (LPPh3 or PEt3) by reactions of [Pt2M4(CCR8] with L leads to displacement of alkynyl ligands from platinum and formation of neutral mononuclear complexes [trans-Pt(CCR)2L2]. © 1995

Luminescent Alkynyl Platinum-Cadmiun Complexes: Structural Characterization of an Unusual Decanuclear Cluster [Pt4Cd6(C=CPh)4(mu-C=CPh)12(mu3-OH)4]

The reaction of (NBu4)2[Pt(CCPh)4] with Cd(ClO4)2·6H2O in a 1:1 molar ratio yields a white solid [PtCd(CCPh)4]n 1 (75% yield) together with yellow crystals of a very unusual decanuclear platinum-cadmium cluster [Pt4Cd6(CCPh)4(-CCPh) 12(3-OH)4] 2 in low yield. Slow diffusion of acetonic solutions of the starting materials under aerobic conditions only produces crystals of 2 which have been shown by an X-ray analysis to be composed of a big hexanuclear cation [Cd6(3-OH)4]8+ and four [Pt(CCPh)4]2- anions, held together by Pt···Cd and ···Cd acetylide interactions. On the other hand, treatment of the insoluble product 1 with 1 equiv of NBu4X yields tetranuclear mixed-metal soluble complexes (NBu4)2[{Pt(-CCPh)4} 2(CdX)2] (X=Cl A, Br 3, CN 4), which contain two platinate fragments connected by two CdX units through Pt···Cd and mainly Cd···C interactions. All complexes are strongly emissive in the solid state at room temperature