Although surfactants have been widely used to tailor the size, shape, and surface properties of nanocrystals and control the pore size and phases of mesoporous frameworks, the use of surfactants as reaction media to grow chalcogenide crystals is unprecedented. In addition, compared with ionic liquids, surfactants are much cheaper and can have multifunctional properties such as acidic, basic, neutral, cationic, anionic, or even block. These features suggest that surfactants could be promising reaction platforms for the development of novel chalcogenide crystals. In this work, we used chalcogenidoarsenates as a model system to demonstrate our strategy. By using three different surfactants as reaction media, we obtained a series of novel thioarsenates ranging from a zero-dimensional (0D) cluster to a three-dimensional (3D) framework, namely, [NH(4)](8)[Mn(2)As(4)S(16)] (1), [Mn(NH(3))(6)][Mn(2)As(2)S(8)(N(2)H(4))(2)] (2), [enH][Cu(3)As(2)S(5)] (3), and [NH(4)][MnAs(3)S(6)] (4). The band gaps (estimated from the steep absorption edges) were found to be 2.31 eV for 1 (0D), 2.46 eV for 2 (1D), 1.91 eV for 3 (2D), and 2.08 eV for 4 (3D). The magnetic study of 4 indicated weak antiferromagnetic behavior. Our strategy of growing crystalline materials in surfactants could offer exciting opportunities for preparing novel crystalline materials with diverse structures and interesting properties.

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We have investigated the electronic structure and optical properties of zinc molybdenum oxide (Zn2Mo3O8) by using both first-principle calculations and experiments. Optical properties of this material is very similar to other ternary oxides of tetravalent molybdenum (A2Mo3O8: A = Mg, Fe, Cd); therefore, this study provides meaningful insight into optical properties and possible phtotovoltaic applicability of these class of metal oxide cluster compounds. We use state-of-the-art methods, based on density functional theory and the GW approximation to the self-energy, to obtain the quasiparticle band structure and absorption spectra of the material. Our calculations shows that Zn2Mo3O8 is a near indirect gap semiconductor with an indirect gap of 3.14 eV. The direct gap of the material is 3.16 eV. We also calculate the optical absorption in the material. Calculated results compare well with UV–visible spectroscopy and spectroscopic ellipsometry measurements done on polycrystalline thin films of Zn2Mo3O8. We show the material has a large excitonic binding energy of 0.78 eV.

Two regioisomeric donor–acceptor–donor triads composed of benzodithiophene and BODIPY exhibit distinct optical and charge transfer properties, and mobilities of ∼10−4 cm2 V−1 s−1.

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