Laser-Materials Interactions: Theory and Experiment (Kay's BES-Surface Kinetics, PNNL Scope #16248)
EMSL Project ID
4792
Abstract
Laser ablation and desorption techniques form the basis of unique methods for producing novel materials, performing sophisticated chemical analysis or medical procedures. Although laser ablation/desorption techniques are utilized extensively across a diverse range of disciplines, detailed mechanistic understanding has proved elusive due to the inherent complexity of the initial laser solid interaction and subsequent particle emission processes. The primary laser absorption may occur through linear or nonlinear mechanisms and through intrinsic or extrinsic photo-centers; further complications are introduced by the many-bodied dynamics that ultimately lead to particle emission. Many of the key processes (i.e. electron/hole-pair recombination, trapping, exciton relaxation, electron/phonon interactions, etc.) occur on a sub-nanosecond time-scale and femtosecond laser studies are needed to clarify the role of ultrafast phenomena involved in laser desorption processes. To obtain detailed understanding of laser desorption a collaborative experimental and theoretical effort is essential as laser desorption dynamics are simply too complicated for experiment or theory alone to unravel. This SOW describes a program to provide support for the theory component of an integrated experimental and theoretical study of laser desorption of ionic crystals (e.g. LiF, KI, KBr, Kcl, NaCl, MgO, and others). Laser dissociation may be used for production of ground and excited state halogen or oxygen atoms. These atoms may be used to etch or oxidize silicon wafer to form thin layers of silicon oxide. The mechanism of halogen and O-atom desorption will be investigated theoretically using techniques developed at UCL.Project Details
Project type
Exploratory Research
Start Date
2003-11-24
End Date
2006-11-15
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members