The inverted perovskite solar cell fabricated using a two-step method exhibited the highest FF of 0.85 and good efficiency of 18% based on CH 3 NH 3 PbI 3 . A small amount of H 2 O was added into PbI 2 /DMF to make a homogenous precursor solution. A high quality PbI 2 film with full coverage was formed on a PEDOT:PSS surface by spin coating of the homogeneous PbI 2 precursor solution. The perovskite film fabricated from the high quality PbI 2 film is highly pure, smooth and very dense even without any pinhole. The champion cell achieves a remarkable fill factor (FF) of 0.85, which is the highest value reported in perovskite solar cells. The FF value is also very reproducible with less than 10% deviation for 50 cells. The cell exhibits no current hysteresis and is stable under both dark and illumination conditions in dry and inert atmospheres. The results not only provide a strategy to fabricate high efficiency inverted perovskite solar cells but also reveal how the water additive in the PbI 2 /DMF solution may affect the properties of PbI 2 and therefore the perovskite film prepared using the two-step method and the overall photovoltaic performance of the corresponding inverted solar cell.

Polyaniline can be inserted in V2O5·nH2O xerogel by in situ oxidative polymerization/intercalation of aniline or anilinium in air. The reaction is facile and topotactic, forming polyaniline as the emeraldine salt. The interlayer separation (5.6 Å) is consistent with a monolayer of polymer chains in the V2O5 framework. Evidence is presented that oxygen acts as an electron acceptor both during the in situ reaction and long after intercalation is complete. The crucial role of oxygen in this reaction is probed and discussed. In an alternative route, anilinium is first intercalated and then, in a second step, is oxidatively polymerized in the xerogel upon exposure of the intercalate sample to air. Upon standing in air (aging), two processes occur independently in these materials:  (a) the partial reoxidation of the reduced V2O5 framework and (b) further oxidative coupling of anilinium and aniline oligomers inside the V2O5 layers, leading to longer chain molecules. These observations are supported by several physicochemical data. The magnetic moment of (PANI) x V2O5·nH2O decreases gradually upon exposure to air, but it does not change when the sample is stored in vacuum. Gel permeation chromatography (GPC) analysis results show that the molecular weight of polyaniline extracted from aged (PANI) x V2O5·nH2O is larger than that extracted from the fresh samples. The thermal stability of polyaniline extracted from aged (PANI) x V2O5·nH2O is better than that extracted from fresh samples. All (PANI) x V2O5·nH2O samples are paramagnetic with a Curie−Weiss and a temperature-independent van Vleck contribution. Variable-temperature 2H-wide-line NMR of (PANI) x V2O5·nH2O shows that the polymer chains are sterically confined with respect to phenyl ring rotation. The room-temperature conductivity of the freshly prepared (PANI) x V2O5·nH2O samples is in the range 10-4−10-1 S/cm depending on the degree of polymerization inside the layers, but the conductivity of aged samples is always greater. Room temperature thermoelectric power is negative and varies (−30 to 200 μV/K) depending on the polymer content and the degree of polymerization.

Dye-sensitized solar cells (DSCs) have been explored for photovoltaic applications because of their low cost and impressive conversion efficiency.[1] A DSC with 10 % efficiency was first demonstrated by Grätzel and co-workers using N3 (cis-di(thiocyanato)bis(2,2'-bipyridyl-4,4-dicarboxylate) ruthenium(II)) as a sensitizer.[2] Progress in optimizing ruthenium-based sensitizers for DSCs has been focused primarily on enhancing the light-harvesting ability, and redshifting the metal-to-ligand charge transfer (MLCT) band. [3][4][5][6][7][8][9][10] These results can be achieved by extending the conjugation length of the anchoring or ancillary ligand. [11][12][13][14][15] Furthermore, retaining the photoinduced interfacial charge separation between the dye molecules and TiO 2 is also a crucial strategy to enhance the performance of DSCs. [16] This strategy is beautifully demonstrated by adding a hole-transport segment on the dye molecule in all-solid-state DSCs. [17,18] However, this concept could not be applied to liquid-state DSCs, [19,20] probably because the ruthenium sensitizers have relatively low light-harvesting capacity and large molecular size.We have shown [21,22] that thiophene-derived units are the good candidates for increasing the conjugation length of the ancillary ligand to increase the light-harvesting ability and red-shift the MLCT band of a ruthenium complex. Herein we reveal that thiophene-derived species can be functionalized easily with a alkyl-substituted hole-transport moiety, such as bis(heptyl)carbazole. Ruthenium complexes with ligands functionalized by thiophene, carbazole, and alkyl chains can be regarded as supersensitizers. The efficiency of a liquidstate DSC based on one of these supersensitizers is 9.72 %, which is 1.2 % higher than that (8.51 %) of the N3-based cell at the same fabrication and efficiency measuring conditions. This is the first demonstration that a carbazole moiety in the dye can enhance the performance of a liquid-state DSC. Furthermore, the terminal alkyl chains on the ancillary ligand were also modulated to explore the impact of the sensitizer size on the cell performance in the DSC. In situ photoelectrochemical measurements were used for the first time to study the intramolecular electron-transfer processes of the oxidized dye.The structures of the supersensitizers CYC-B6S and CYC-B6L are depicted in Figure 1. The electronic absorption spectra of these supersensitizers and N3 measured in DMF are displayed in Figure 2, and the optical data are summarized in Table 1. The absorption spectra of the supersensitizers show that the band centered at around 550 nm (which is the characteristic metal-to-ligand charge-transfer (MLCT) transition) is stronger and more red-shifted than that for N3. These results indicate that the spectral response of ruthenium

1 This article will form part of a virtual special issue on advanced neutron scattering instrumentation, marking the 50th anniversary of the journal.QUOKKA is a 40 m pinhole small-angle neutron scattering instrument in routine user operation at the OPAL research reactor at the Australian Nuclear Science and Technology Organisation. Operating with a neutron velocity selector enabling variable wavelength, QUOKKA has an adjustable collimation system providing source-sample distances of up to 20 m. Following the largearea sample position, a two-dimensional 1 m 2 position-sensitive detector measures neutrons scattered from the sample over a secondary flight path of up to 20 m. Also offering incident beam polarization and analysis capability as well as lens focusing optics, QUOKKA has been designed as a general purpose SANS instrument to conduct research across a broad range of scientific disciplines, from structural biology to magnetism. As it has recently generated its first 100 publications through serving the needs of the domestic and international user communities, it is timely to detail a description of its asbuilt design, performance and operation as well as its scientific highlights. Scientific examples presented here reflect the Australian context, as do the industrial applications, many combined with innovative and unique sample environments. research papers J. Appl. Cryst. (2018). 51, 294-314 Kathleen Wood et al. QUOKKA 295 Figure 1 QUOKKA instrument layout. research papers J. Appl. Cryst. (2018). 51, 294-314 Kathleen Wood et al. QUOKKA 297 Figure 3(a) Attenuator wheel. (b) Automatic aperture changer. (c) Sample environment area, showing the extendable bellows on the left and the 20position sample changer on the right. Downstream of the sample changer, the entrance to the detector tank is visible. (d) Beamstop mechanism, with the six beamstops all in the 'in beam' position.research papers J. Appl. Cryst. (2018). 51, 294-314 Kathleen Wood et al. QUOKKA 299 research papers J. Appl. Cryst. (2018). 51, 294-314 Kathleen Wood et al. QUOKKA 301 research papers J. Appl. Cryst. (2018). 51, 294-314 Kathleen Wood et al. QUOKKA 313

We report the encapsulation of polyaniline filaments in mesoporous hosts with 3 nm channel diameter. The channel size permits encapsulation of several polyaniline chains, and the resulting filaments show microwave conductivity. Processing of information at the molecular level is an intriguing and important challenge. Efforts to create electronic functions and devices based on molecules instead of bulk semiconductors are inspired by the anticipated enormous increase in computing speed and storage density.'Y2 However, this approach requires that communication with nanometer structures or molecules can be established. A major challenge is to electrically isolate the conducting structures, and to achieve charge transfer with low fields as in metallic wires. We have recently demonstrated the encapsulation of several different conjugated polymers such as polypyrrole in the welldefined channels of zeolite molecular sievese3 The synthesis of polyaniline in sol-gel-derived silica gel,4 and the template synthesis of conducting polymers in the pores (ca. 0.1-1 pm) of insulating host membranes has also been reported.5 Here we demonstrate the stabilization of conducting polyaniline filaments in the 3 nm wide hexagonal channels of transition-metal-containing mesoporous aluminosilicate host6 MCM-41.Polyaniline is an unusual conducting polymer because its conductivity is not only controlled by the degree of chain oxidation but also by the level of protonation of [ (-BNHBNH-),(-BN=Q=N-)~.,l., leading to the salt ((PhNH-)A,),.7s In the conducting salt form (emeraldine salt or PANI) x and y are close to 0.5; B, Q, and Ph are C6H4 rings in the benzenoid, quinoid, and intermediate states, respectively, and HA is a strong acid. A proton-induced spin unpairing process on imine nitrogens of the emeraldine salt form of polyaniline is believed to create a conducting polaron lattice. Clays and zeolites ion-exchanged with Cu2+ or Fe3+ have been shown to oxidatively polymerize various monomers of conjugated polymers such as anilines,g pyrrole,lO and thiophene and its d e r i v a t i~e s~~J l inside their cavities. The in situ oxidative polymerization/intercalation of conducting polymers in layered materials containing strong oxidants has also been demonstrated.12Here we have carried out in situ oxidative adsorption/ polymerization of aniline vapor in Cu-MCM (or Fe-MCM), either in the absence or presence of air (details in Table 1). The encapsulated emeraldine salt was formed by first adsorbing aniline vapor into the host;13 a maximum of 0.3 g of aniline adsorbed in 1.0 g of Cu-MCM or Fe-MCM (Table 1). Under exclusion of air, the saturated pink adduct (AN-CuMCM-0, AN-FeMCM-0) was then immersed in an acidic aqueous solution of peroxydisulfate, and a drastic color change to dark green was observed. After thorough washing with water, the materials were dried under vacuum. A typical polymer loading is 0.16 g/1.00 g of Cu-MCM host. The following will address the nature of the encapsulated material, its location, and its ac conductivity.The Cu or ...

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