Photodissociation of semiconductor positive cluster ions

Journal Article · Mon Feb 01 00:00:00 EST 1988 · J. Chem. Phys.; (United States)

DOI:https://doi.org/10.1063/1.454145· OSTI ID:5714663

Zhang, Q; Liu, Y; Curl, R F; Tittel, F K; Smalley, R E

Laser photofragmentation of Si, Ge, and GaAs positive cluster ions prepared by laser vaporization and supersonic beam expansion has been investigated using tandem time-of-flight mass spectrometry. Si clusters up to size 80, Ge clusters to size 40, and GaAs clusters up to a total of 31 atoms were studied. Si/sup +//sub n/ and Ge/sup +//sub n/ for n = 12--26 give daughter ions of about half their original size. For both Si and Ge, this apparent positive ion fissioning appears to go over with increasing n to neutral loss of seven and ten, but for Si/sup +//sub n/ the range of n values where this is observed is rather small. At low fluences, the larger Ge/sup +//sub n/ clusters up to the maximum size observed (50) sequentially lose Ge/sub 10/ (and in some cases with lower intensity Ge/sub 7/). Larger Si/sup +//sub n/ clusters (n>30) always fragment primarily to produce positive ion clusters in the 6--11 size range with a subsidiary channel of loss of a single Si atom. At high laser fluences, Ge/sup +//sub n/ also fragments to produce primarily positive ion clusters in the 6--11 size range with an intensity pattern essentially identical to Si/sup +//sub n/ at similar fluences. Ga/sub x/As/sup +//sub y/ clusters lose one or more atoms in what is probably a sequential process with positive ion clusters in which the total number of atoms, x+y, is odd being more prominent.

• Research Organization: Rice Quantum Institute, Departments of Chemistry and Electrical Engineering, Rice University, Houston, Texas 77251
• OSTI ID: 5714663
• Journal Information: J. Chem. Phys.; (United States), Vol. 88:3
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GALLIUM ARSENIDES
MOLECULAR BEAMS
MOLECULAR IONS
GERMANIUM
PHOTOLYSIS
SILICON
ADDUCTS
EVAPORATION
LASER RADIATION
MASS SPECTROSCOPY
SIZE
SUPERSONIC FLOW
ARSENIC COMPOUNDS
ARSENIDES
BEAMS
CHARGED PARTICLES
CHEMICAL REACTIONS
DECOMPOSITION
ELECTROMAGNETIC RADIATION
ELEMENTS
FLUID FLOW
GALLIUM COMPOUNDS
IONS
METALS
PHASE TRANSFORMATIONS
PHOTOCHEMICAL REACTIONS
PNICTIDES
RADIATIONS
SEMIMETALS
SPECTROSCOPY
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory
640301 - Atomic
Molecular & Chemical Physics- Beams & their Reactions