Synthesis of two novel porous framework hybrid materials, [Co(4,4′-bipy)V 2 O 6 ] (1) and [{Co 2 (4,4′-bipy) 3 (H 2 O) 2 }V 4 O 12 ]‚2H 2 O (2), and their characterization by infrared spectroscopy, thermogravimetry, elemental analysis, manganometric titration, surface area measurement, bond valence sum calculations, temperature-dependent magnetic susceptibility measurement, and single-crystal X-ray structure analyses is described. Both compounds exhibit remarkable thermal stability. The three-dimensional structures of 1 and 2 are composed of fused {VO 4 } motifs linked by {Co(4,4′-bipy)} coordination polymers. The structure of 1 is comprised of {CoO 3 N 2 } trigonal bipyramids, linked in two dimensions by corner-sharing {VO 4 } tetrahedra and in the third dimension by the 4,4′-bipyridine ligands. In the bimetallic layers, the cobalt centers are bridged alternately by {VO 4 } and {V 2 O 7 } units, generating alternating eightmembered {Co 2 V 2 O 4 } and twelve-membered {Co 2 V 4 O 6 } rings. The crystal structure of 2 consists of a novel three-dimensional network containing two types of octahedral Co 2+ ions linked by a {V 2 O 7 } group. The cobalt centers in 2 are linked in three dimensions by bridging 4,4′-bipyridine ligands. The structure contains rather large channels parallel to the c-axis. A disordered water molecule of crystallization is present in the channels. Crystal data for C 10 H 8 N 2 O 6 CoV 2 , 1: triclinic space group P1 h (No. 2), a ) 8.1517(4) Å, b ) 8.5794(4) Å, c ) 10.1233(5) Å, R ) 87.0170(10)°, ) 75.9610(10)°, γ ) 75.1740(10)°, V ) 663.94(6) Å 3 , Z ) 2, D calcd ) 2.066 Mg‚m -3 , R1 ) 0.0252 (all data), wR2 ) 0.0669. Crystal data for C 15 H 16 N 3 O 8 -CoV 2 , 2: monoclinic space group C2/c (No. 15), a ) 30.4457(13) Å, b ) 11.3540(5) Å, c ) 11.5836(5) Å, ) 106.5390(10)°, V ) 3838.6(3) Å 3 , Z ) 8, D calcd ) 1.824 Mg‚m -3 , final R1 ) 0.0447 (all data), wR2 ) 0.1259.

A small cross-section of silver nanoparticles (AgNPs) placed at the rear-part of the solar cell avoids the parasitic absorption of the nanoparticles which is the biggest barrier for plasmonic structures when acting as photocurrent enhancers. Herein, we demonstrate p-i-n planar perovskite solar cells with the structure ITO/PEDOT:PSS/MAPbI3/PCBM/Ni:Au, where the PCBM electron extraction layer (EEL) was intentionally modified with variable amounts of AgNPs. The addition of small amounts of AgNPs (e.g., 5 wt. %) into the PCBM improved the overall reproducibility and reliability of the solar cell fabrication process after optimization. Plasmonic simulations suggest that any plasmonic-optical effects are relatively small compared to sample absorbance due to perovskite alone. It has been concluded that plasmonic-electrical effects play a major role in averaged performance improvement. Therefore, the addition of small AgNPs in low concentration to the EEL layer accounts for higher Jsc, Voc and FF as a result of a better perovskite coverage by the EEL and an improved charge carrier collection as evidenced by morphological and electrical analysis.

Inorganic-organic hybrid materials [Ni(py) 4 ] 2 V 10 O 29 (1) and [Ni 2 (py) 5 (H 2 O) 3 ]V 4 O 12 (2) have been synthesized and characterized by infrared spectroscopy, thermogravimetry, magnetometry, and complete single crystal structure analysis. The crystal structures of 1 and 2 exhibit novel three-dimensional covalent networks. The framework structure in 1 contains polyoxometallate groupings of stoichiometry {V 10 O 29 } which are constructed from two cyclic {V 4 O 12 } units bound to centrosymmetric {V 2 O 7 } species. V-O-Ni bridges in the a-and b-directions join these units to two crystallographically independent trans-[Ni(py) 4 O 2 ] octahedra. The nickel-and vanadium-based moieties occupy alternating channels along the c-direction. The structure of 2 consists of octahedral species [Ni(py) 3 (H 2 O)O 2 ] and [Ni(py) 2 (H 2 O) 2 O 2 ] which are linked into a three-dimensional covalent network by the sharing of oxygen atom vertices with tetrahedral {VO 4 } groups. Compounds 1 and 2 are thermally stable up to 200 and 175 °C, respectively.Both compounds show Curie-Weiss type magnetic behavior over the temperature range 1.9-300 K. The effective magnetic moment in both cases is 3.0 µ B , revealing the presence of significant orbital contribution. Single ion magnetization as a function of magnetic field showed linear behavior for 1 and 2 over the range of 0-1 T. At a magnetic field of 9 T, 1 approaches saturation at 2 µ B per Ni 2+ ion, whereas 2 does not approach saturation well.

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