期刊
CHEMISTRY OF MATERIALS
卷 25, 期 21, 页码 4330-4339出版社
AMER CHEMICAL SOC
DOI: 10.1021/cm402505p
关键词
surfactants; amphiphiles; electrodeposition; layered double hydroxides; self-assembly; lamellar; nanostructures; anisotropy
资金
- U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering [DE-FG02-00ER45810]
- U.S. National Science Foundation
- U.S. Department of Defense, Air Force Office of Scientific Research, National Defense Science and Engineering Graduate (NDSEG) Fellowship
- NSF-NSEC
- NSF-MRSEC
- Keck Foundation
- State of Illinois
- Northwestern University
- MRSEC program of the National Science Foundation at the Materials Research Center of Northwestern University [DMR-0520513]
- U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences [DE-AC02-06CH11357]
Previous work has shown that nanoscale lamellar inorganic organic hybrid materials can be synthesized on transparent conductive substrates via the electrodeposition of Zn(OH)(2) in the presence of conjugated surfactants. These surfactants introduce p-type semiconducting supramolecular phases; thus, following conversion of the Zn(OH)(2) phase to the n-type semiconductor ZnO, the lamellar hybrids exhibit high photoconductive gains and can exhibit photovoltaic activity. We report here on a family of carboxylated terthiophene-based surfactants designed with systematic modifications to molecular geometry, valency, and flexibility to investigate how these features affect the synthesis of the p-type/n-type semiconducting hybrid materials. We use scanning electron microscopy (SEM) and two-dimensional (2D) grazing-incidence X-ray diffraction (2D-GIXD) to correlate molecular features of the surfactants with growth and orientation of the nanoscale lamellae that form during electrodeposition on either hydrophilic or hydrophobic substrates. We find that molecularly flexible, monovalent terthiophene amphiphiles with linear geometries generate highly oriented and homogeneous films of the nanoscale hybrids, whereas T-shaped geometries, rigid molecules, or divalent surfactants tend to produce more heterogeneous and isotropically oriented lamellae under the same conditions. The critical aggregation concentrations (CAC) of the amphiphiles are higher than the concentrations used during electrodeposition, indicating that the growth and orientation of lamellar structures are mediated by surfactant-substrate interactions, rather than the assemblies they form in bulk solutions. Molecular design in these hybrid systems is a key factor in optimizing function, since dense and macroscopically oriented growth is necessary in both photoconductivity and photovoltaic efficiency of solar cells.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据