AVS 54th International Symposium | |
Surface Science | Friday Sessions |
Session SS2+EM+TF-FrM |
Session: | Organic Films II: Semiconductors and C@sub 60@ |
Presenter: | G.-Y. Liu, University of California, Davis |
Authors: | J.-J. Yu, University of California, Davis Y.H. Tan, University of California, Davis X. Li, University of California, Davis P.K. Kuo, Wayne State University G.-Y. Liu, University of California, Davis |
Correspondent: | Click to Email |
Using a scanning probe lithography method known as nanografting in conjunction with knowledge of self-assembly chemistry, regulation of the heterogeneity of self-assembled monolayers (SAMs) is demonstrated. It is known that phase segregated domains would form if SAMs are grown from thiol solutions of mixed compositions. The size and distribution of these domains depend on the interplay between reaction kinetics and dynamics, which can be regulated by varying the reaction conditions including concentration, temperature and reaction time. The reaction mechanism in nanografting, however, differs significantly from self-assembly in the conventional mix-and-grow methods. The spatial confinement in nanografting bypasses the lying-down to standing up transition process, and thus leads to a much fast kinetics. Knowledge of the reaction pathways enables development of methods for shifting the interplay between the kinetics and thermodynamics in SAM formation, and thus the heterogeneity of mixed SAMs. By varying fabrication parameters such as shaving speed, and reaction conditions such as concentration and ratio of the components, the lateral heterogeneity can be adjusted ranging from near molecular mixing to segregated domains of several to tens of nanometers.