Photoexcited carrier trapping and recombination at Fe centers in GaN

Journal Article · Tue Jun 07 00:00:00 EDT 2016 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4953219· OSTI ID:22596773

Uždavinys, T. K. ^[1]; Leach, J. H.; Evans, K. R. ^[2]; Look, D. C. ^[3]

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1. Department of Materials and Nano Physics, KTH Royal Institute of Technology, Electrum 229, 16440 Kista (Sweden)
2. Kyma Technologies Inc., 8829 Midway West Road, Raleigh, North Carolina 27617 (United States)
3. Semiconductor Research Center, Wright State University, Dayton, Ohio 45435 (United States)

Fe doped GaN was studied by time-resolved photoluminescence (PL) spectroscopy. The shape of PL transients at different temperatures and excitation powers allowed discrimination between electron and hole capture to Fe{sup 3+} and Fe{sup 2+} centers, respectively. Analysis of the internal structure of Fe ions and intra-ion relaxation rates suggests that for high repetition rates of photoexciting laser pulses the electron and hole trapping takes place in the excited state rather than the ground state of Fe ions. Hence, the estimated electron and hole capture coefficients of 5.5 × 10{sup −8} cm{sup 3}/s and 1.8 × 10{sup −8} cm{sup 3}/s should be attributed to excited Fe{sup 3+} and Fe{sup 2+} states. The difference in electron capture rates determined for high (MHz) and low (Hz) (Fang et al., Appl. Phys. Lett. 107, 051901 (2015)) pulse repetition rates may be assigned to the different Fe states participating in the carrier capture. A weak temperature dependence of the electron trapping rate shows that the potential barrier for the multiphonon electron capture is small. A spectral feature observed at ∼420 nm is assigned to the radiative recombination of an electron in the ground Fe{sup 2+} state and a bound hole.

• OSTI ID: 22596773
• Journal Information: Journal of Applied Physics, Vol. 119, Issue 21; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
CARRIERS
DOPED MATERIALS
ELECTRON CAPTURE
ELECTRONS
EXCITATION
EXCITED STATES
GALLIUM NITRIDES
GROUND STATES
HOLES
IRON IONS
LASERS
PHOTOLUMINESCENCE
PULSES
RECOMBINATION
RELAXATION
SPECTROSCOPY
TEMPERATURE DEPENDENCE
TIME RESOLUTION
TRAPPING