• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.02a
• /
• pp.369-369
• /
• 2010

Adsorption and ordering of methionine molecules on Ge(100) surface have been studied using high resolution photoemission spectroscopy and low-energy electron diffraction (LEED) to investigate the adsorption structure as a function of coverage. Analysis of C 1s, S 2p, N 1s, and O 1s core levels reveals quite different according to methionine coverage. We found that the relative population of the two types of thiolates induces a structural change in the ordering from $2\;{\times}\;1$ to $1\;{\times}\;1$. Such an unusual evolution of the methionine adsorption on the Ge(100) surface is discussed in relation to chemical reactions and possible molecular rearrangement on the surface.

• Proceedings of the Korean Vacuum Society Conference
• /
• 1995.06a
• /
• pp.114-114
• /
• 1995

• Proceedings of the Korean Vacuum Society Conference
• /
• 1994.06a
• /
• pp.147-147
• /
• 1994

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.147-148
• /
• 2005

We report on high-performance organic field-effect transistors by promoting surface-mediated two-dimensional molecular ordering in organic semiconductor. To achieve this goal, we have controlled the intermolecular interaction at the interface between organic semiconductor and the insulator substrate.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2008.02a
• /
• pp.159-159
• /
• 2008

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1996.05a
• /
• pp.232-234
• /
• 1996

We have investigated the effect of molecular structure of polymer of rubbed polyimide (PI) films for surface liquid crystal alignment. To obtain surface alignment effect of Polymer molecular structure, we measured the polar (out of plane-tilt) anchoring strength and surface ordering of 5CB on rubbed PI surfaces. We have found that the polar anchoring strength of 5CB is depend on the polymer molecular structure of these unidirectionally rubbed PI surfaces.

• Proceedings of the KIEE Conference
• /
• 1998.07d
• /
• pp.1508-1510
• /
• 1998

Recent development of scanning probe microscope techniques has made it possible to investigate, not only microscopic surface topography, but also physical and chemical properties on the nanometer-scale. The scanning Maxwell-stress microscopy (SMM) is surface characterization tool capable of mapping both the surface topography and electrical properties, such as surface potential, surface charge dielectric constant of thin films with a nanometer-scale resolution by means of the AC voltage driven oscillation of metal coated cantilever. In this study, we observed the surface potential distribution and molecular ordering in thin films. We have demonstrated that the SMM can be used for imaging surface potential distribution over the film surface and also be used for detecting surface changes in thin films. This is first step towards the understanding of electrical phenomena in organic and inorganic materials, biological system with SMM.

• Proceedings of the Korean Magnestics Society Conference
• /
• 2007.05a
• /
• pp.189.1-189.1
• /
• 2007

• Journal of the Korean Vacuum Society
• /
• v.7 no.3
• /
• pp.187-194
• /
• 1998

InGaAsP epitaxial layers lattice matched to InP were grown at 600 and $620^{\circ}C$ by low pressure metalorganic chemical vapor deposition. Solid phase composition of group III was controlled by the diffusion flux gas phase to the reachion surface. For the case of group V, the difference of As and P vapor pressure and pyrolysis efficiency of $PH_3$and $AsH_3$ mainly determined their in corporation into solid. An abnormal behavior of peak energy shift was observed below 75K in temperature variant photoluminescence study. This abnormal behavior was explained by the difference in order of ordering which makes spatial variation of energy gap in InGaAsP layer and this explanation was supported by the analyses of transmission electron microscopy and transmission spectroscopy.

• Proceedings of the Polymer Society of Korea Conference
• /
• 2006.10a
• /
• pp.189-189
• /
• 2006

The self-assembly of supramolecular dendrimers allows the rapid construction of nanosized structures with regularly ordered features that depend on the shape of the molecules and the relative strength of the intra-and intermolecular interactions. Here we report on a dramatic improvement in the degree of control and selectivity in the orientation of fan-shaped supramolecular molecules over a large area, which has been achieved by confined geometries and applied fields. The order and orientation of supramolecular dendrimers can be controlled by surface anchoring in confined geometries. POM, SEM, TEM, AFM and XRD results show that the molecules form the complicated defect-ordering in the microchannels with different feature sizes. We show that these defect domains are strongly influenced by the boundary and feature size of the surfaces. This technique can be used to create a grain size in the plane of the film that is much larger than that which can be achieved using previously reported soft-material based pattering.