EPR studies of e-beam and gamma irradiated ZnGeP{sub 2}: A nonlinear optical material for the infrared

Conference · Sun Dec 31 04:00:00 EST 1995

OSTI ID:375995

Rakowsky, M H; Lauderdale, W J ^[1]; Mantz, R A ^[2]; Pandey, R ^[3]; Drevinsky, P J ^[4]

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1. Air Force Academy, CO (United States). Frank J. Seiler Research Lab.
2. Phillips Lab., Edwards AFB, CA (United States)
3. Michigan Technological Univ., Houghton, MI (United States). Dept. of Physics
4. Phillips Lab., Hanscom AFB, MA (United States)

Zinc germanium phosphide is a nonlinear optical material for efficient frequency conversion in the mid-IR spectral region. One challenge in the development of ZnGeP{sub 2} is to reduce the near band edge absorption in the 0.7 to 2.5 micron region. Several methods have been used to ascertain the origin of this absorbance. One method, electron paramagnetic resonance (EPR), has been used to characterize the paramagnetic native acceptor in ZnGeP{sub 2} by studying as-grown, thermally annealed, electron-beam irradiated, and gamma irradiated single crystals. Each of these processing routines improves the optical transparency with a concurrent decrease in the concentration of paramagnetic centers and defect site symmetry as seen in the EPR spectra. High energy e-beam and gamma irradiation may cause compensation, movement, or creation of new defects. In addition, nuclear magnetic resonance (NMR) has been used to further characterize several samples of as-grown, annealed and polycrystalline ZnGeP{sub 2}. Preliminary calculations of the defect energetics have been conducted using atomistic simulation techniques employing the shell model to describe the lattice. Interionic potentials between the constituent ions were obtained by performing quantum cluster calculations on ZnGeP{sub 2}.

• OSTI ID: 375995
• Report Number(s): CONF-941144--; ISBN 1-55899-255-3
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
CRYSTAL DEFECTS
ELECTRON SPIN RESONANCE
FREQUENCY CONVERTERS
GERMANIUM PHOSPHIDES
LASER MATERIALS
OPTICAL PROPERTIES
PHYSICAL RADIATION EFFECTS
ZINC PHOSPHIDES