{"id":5808,"date":"2022-06-13T14:43:36","date_gmt":"2022-06-13T06:43:36","guid":{"rendered":"https:\/\/sites.gtiit.edu.cn\/research\/?post_type=mec-events&p=5808"},"modified":"2022-06-13T14:43:36","modified_gmt":"2022-06-13T06:43:36","slug":"20220705","status":"publish","type":"mec-events","link":"https:\/\/sites.gtiit.edu.cn\/research\/events\/20220705\/","title":{"rendered":"Organic functionalization of silicon surfaces \u2013 from mechanisms to multilayers"},"content":{"rendered":"

Title<\/strong><\/span><\/p>\n

Organic functionalization of silicon surfaces \u2013 from mechanisms to multilayers<\/strong><\/p>\n

Speaker<\/span><\/strong><\/p>\n

Prof. Michael D\u00fcrr<\/strong> (Institute of Applied Physics, Justus Liebig University Giessen, Germany)<\/p>\n

Host<\/span><\/strong><\/p>\n

Prof. Kai Huang<\/strong> (GTIIT, Chemistry)<\/p>\n

Time and Location<\/span><\/strong><\/p>\n

Jul. 05 2022, Tuesday, 4:00pm-5:00pm(China Time),\u00a0 E211 (Education Building, 2nd floor)<\/p>\n

Language<\/span><\/strong><\/p>\n

English<\/p>\n

Zoom Link<\/span><\/strong><\/p>\n

https:\/\/gtiit.zoom.us\/j\/94609938903<\/p>\n

Abstract<\/strong><\/span><\/p>\n

The adsorption of organic molecules on silicon has been the subject of intense research due to the potential applications of organic functionalization of silicon surfaces. The high reactivity of the silicon dangling bonds towards almost all organic functional groups, however, presents a major hindrance for the first basic reaction step of such a functionalization, i.e., chemoselective attachment of bifunctional organic molecules on the pristine silicon surface. Due to this high reactivity, the final adsorption products typically consist of a mixture of molecules adsorbed via different functional groups. For the preparation of well-ordered organic layers on silicon, it is thus important to learn how to control the reactions of the single functional groups.<\/p>\n

Using various spectroscopic techniques, such as XPS, UPS, and nonlinear optics, in combination with scanning tunneling microscopy and molecular beam techniques, we investigated in detail the reaction mechanisms, kinetics, and dynamics of different functional groups on Si(001). We make use of these results in order to control the respective reactions by changing the molecules\u2019 very properties. In particular, our main strategy for the functionalization of Si(001) is then based on substituted cyclooctynes, as cyclooctyne\u2019s strained triple bond is associated with a direct adsorption channel on Si(001), in contrast to almost all other organic molecules, which adsorb via weakly bound intermediates [1]. As a consequence, cyclooctyne derivatives with different functional side groups, such as an ether, ester or terminal alkyne group, react on Si(001) selectively via the strained cyclooctyne triple bond while leaving the side groups intact [1,2]. The latter can thus be used for further reactions, e.g., using click-chemistry, when building-up molecular multilayers on the silicon substrate [3,4]. Electronic excitation [5] and hyperthermal energy distributions of the incoming molecules [6] are investigated as further means of control.<\/p>\n