Surface Modification of ZnO Using Triethoxysilane-Based Molecules Export

@article{citeulike:3483434, abstract = {Abstract: Zinc oxide (ZnO) is an important material for hybrid inorganicorganic devices in which the characteristics of the interface can dominate both the structural and electronic properties of the system. These characteristics can be modified through chemical functionalization of the ZnO surface. One of the possible strategies involves covalent bonding of the modifier using silane chemistry. Whereas a significant body of work has been published regarding silane attachments to glass and SiO2, there is less information about the efficacy of this method for controlling the surface of metal oxides. Here we report our investigation of molecular layers attached to polycrystalline ZnO through silane bonding, controlled by an amine catalyst. The catalyst enables us to use triethoxysilane precursors and thereby avoid undesirable multilayer formation. The polycrystalline surface is a practical material, grown by solgel processing, that is under active exploration for device applications. Our study included terminations with alkyl and phenyl groups. We used water contact angles, infrared spectroscopy, and X-ray photoemission spectroscopy to evaluate the modified surfaces. Alkyltriethoxysilane functionalization of ZnO produced molecular layers with submonolayer coverage and evidence of disorder. Nevertheless, a very stable hydrophobic surface with contact angles approaching 106° resulted. Phenyltriethoxysilane was found to deposit in a similar manner. The resulting surface, however, exhibited significantly different wetting as a result of the nature of the end group. Molecular layers of this type, with a variety of surface terminations that use the same molecular attachment scheme, should enable interface engineering that optimizes the chemical selectivity of ZnO biosensors or the charge-transfer properties of ZnOpolymer interfaces found in oxideorganic electronics.}, address = {Department of Physics, Colorado School of Mines, Golden, Colorado, and National Renewable Energy Laboratory, Golden, Colorado}, author = {Allen, C. G. and Baker, D. J. and Albin, J. M. and Oertli, H. E. and Gillaspie, D. T. and Olson, D. C. and Furtak, T. E. and Collins, R. T.}, citeulike-article-id = {3483434}, citeulike-linkout-0 = {http://dx.doi.org/10.1021/la802621n}, citeulike-linkout-1 = {http://pubs.acs.org/doi/abs/10.1021/la802621n}, day = {31}, doi = {10.1021/la802621n}, journal = {Langmuir}, keywords = {ca, ftir, otes, xps, zno}, month = {October}, posted-at = {2008-11-05 22:53:00}, priority = {2}, title = {Surface Modification of ZnO Using Triethoxysilane-Based Molecules}, url = {http://dx.doi.org/10.1021/la802621n}, year = {2008} }

TY - JOUR ID - citeulike:3483434 L3 - citeulike-article-id:3483434 N2 - Abstract: Zinc oxide (ZnO) is an important material for hybrid inorganicorganic devices in which the characteristics of the interface can dominate both the structural and electronic properties of the system. These characteristics can be modified through chemical functionalization of the ZnO surface. One of the possible strategies involves covalent bonding of the modifier using silane chemistry. Whereas a significant body of work has been published regarding silane attachments to glass and SiO2, there is less information about the efficacy of this method for controlling the surface of metal oxides. Here we report our investigation of molecular layers attached to polycrystalline ZnO through silane bonding, controlled by an amine catalyst. The catalyst enables us to use triethoxysilane precursors and thereby avoid undesirable multilayer formation. The polycrystalline surface is a practical material, grown by solgel processing, that is under active exploration for device applications. Our study included terminations with alkyl and phenyl groups. We used water contact angles, infrared spectroscopy, and X-ray photoemission spectroscopy to evaluate the modified surfaces. Alkyltriethoxysilane functionalization of ZnO produced molecular layers with submonolayer coverage and evidence of disorder. Nevertheless, a very stable hydrophobic surface with contact angles approaching 106° resulted. Phenyltriethoxysilane was found to deposit in a similar manner. The resulting surface, however, exhibited significantly different wetting as a result of the nature of the end group. Molecular layers of this type, with a variety of surface terminations that use the same molecular attachment scheme, should enable interface engineering that optimizes the chemical selectivity of ZnO biosensors or the charge-transfer properties of ZnOpolymer interfaces found in oxideorganic electronics. JF - Langmuir AD - Department of Physics, Colorado School of Mines, Golden, Colorado, and National Renewable Energy Laboratory, Golden, Colorado TI - Surface Modification of ZnO Using Triethoxysilane-Based Molecules KW - ca KW - ftir KW - otes KW - xps KW - zno AU - Allen, CG AU - Baker, DJ AU - Albin, JM AU - Oertli, HE AU - Gillaspie, DT AU - Olson, DC AU - Furtak, TE AU - Collins, RT PY - 2008/10/31/ UR - http://dx.doi.org/10.1021/la802621n ER -