Complexation Chemistry in N,N-Dimethylformamide-Based Molecular Inks for Chalcogenide Semiconductors and Photovoltaic Devices.

Molecular inks based on dimethyl sulfoxide, thiourea (TU), and metal salts have been used to form high optoelectronic quality semiconductors and have led to high power conversion efficiencies for solution-processed photovoltaic devices for CuZnSn(S,Se) (CZTS), CuZn(Ge,Sn)(S,Se) (CZGTS), CuIn(S,Se) (CIS), and Cu(In,Ga)(S,Se) (CIGS). However, several metal species of interest, including Ag(I), In(III), Ge(II), and Ge(IV), either have low solubility (requiring dilute inks) or lead to precipitation or gelation. Here, we demonstrate that the combination of N,N-dimethylformamide (DMF) and TU has the remarkable ability to form intermediate-stability acid-base complexes with a wide number of metal chloride Lewis acids (CuCl, AgCl, ZnCl, InCl, GaCl, SnCl, GeCl, and SeCl), to give high-concentration stable molecular inks.

Tricontinuous Cubic Nanostructure and Pore Size Patterning in Mesostructured Silica Films Templated with Glycerol Monooleate.

The fabrication of nanostructured films possessing tricontinuous minimal surface mesophases with well-defined framework and pore connectivity remains a difficult task. As a new route to these structures, we introduce glycerol monooleate (GMO) as a template for evaporation-induced self-assembly. As deposited, a nanostructured double gyroid phase is formed, as indicated by analysis of grazing-incidence small-angle x-ray scattering data.

Characterization of lipid-templated silica and hybrid thin film mesophases by grazing incidence small-angle X-ray scattering.

The nanostructure of silica and hybrid thin film mesophases templated by phospholipids via an evaporation-induced self-assembly (EISA) process was investigated by grazing-incidence small-angle X-ray scattering (GISAXS). Diacyl phosphatidylcholines with two tails of 6 or 8 carbons were found to template 2D hexagonal mesophases, with the removal of lipid from these lipid/silica films by thermal or UV/O3 processing resulting in a complete collapse of the pore volume. Monoacyl phosphatidylcholines with single tails of 10-14 carbons formed 3D micellular mesophases; the lipid was found to be extractable from these 3D materials, yielding a porous material.