Ether Chemistry On Si(100) And Desorption Kinetics Of Corresponding Alkyls And Alkoxides
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Authors
Pohlman, Andrew
Issue Date
2018
Type
Dissertation
Language
Keywords
Desorption , Non-adiabatic , Silicon , Surface , surface kinetics
Alternative Title
Abstract
The desorption kinetics of a series of alkyls and alkoxides from the Si(100) surface weremeasured to investigate the details of the hydride elimination desorption mechanism.Following the analysis of temperature programmed desorption experiments inconjunction with electronic structure calculations, it was determined that the hydrideelimination mechanism exhibits nonadiabatic behavior. The mechanism most consistentwith the experimental kinetics involves a spin-crossing due to the electronic excitation ofthe surface dimer accepting the eliminated hydride. The energetics for the initialelectronic excitation agrees closely with the experimental kinetic parameters for the ratelimiting step of the desorption reaction. This desorption mechanism was determined to beconsistent between alkyl and alkoxide surface species and their different respectivedesorption reaction channels. The hydride elimination mechanism was successful indescribing the desorption reactions for more complex adsorbate systems, such as linearand cyclic ethers, which produced a mixture of surface products.