Investigation of the recombination mechanism of excess carriers in undoped BaSi{sub 2} films on silicon

Journal Article · Mon Oct 15 04:00:00 EDT 2012 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4759246· OSTI ID:22089488

Hara, K. O.; Usami, N. ^[1]; Toh, K.; Baba, M.; Toko, K. ^[2]; Suemasu, T. ^[3]

---

1. Institute for Materials Research, Tohoku University, Sendai 980-8577 (Japan)
2. Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan)
3. Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Chiyoda, Tokyo 102-0075 (Japan)

Excess-carrier recombination mechanisms in undoped BaSi{sub 2} epitaxial films grown by molecular beam epitaxy on n-type silicon substrates have been studied by the microwave-detected photoconductivity decay measurement. The measured excess-carrier decay is multiexponential, and we divided it into three parts in terms of the decay rate. Measurement with various excitation laser intensities indicates that initial rapid decay is due to Auger recombination, while the second decay mode with approximately constant decay to Shockley-Read-Hall recombination. Slow decay of the third decay mode is attributed to the carrier trapping effect. To analyze Shockley-Read-Hall recombination, the formulae are developed to calculate the effective lifetime (time constant of decay) from average carrier concentration. The measurement on the films with the thickness of 50-600 nm shows that the decay due to Shockley-Read-Hall recombination is the slower in the thicker films, which is consistent with the formulae. By fitting the calculated effective lifetime to experimental ones, the recombination probability is extracted. The recombination probability is found to be positively correlated with the full width at half-maximum of the X-ray rocking curves, suggesting that dislocations are acting as recombination centers.

• OSTI ID: 22089488
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 8 Vol. 112; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
AUGER EFFECT
BARIUM COMPOUNDS
CARRIERS
DISLOCATIONS
EXCITATION
FILMS
LAYERS
LIFETIME
MICROWAVE RADIATION
MOLECULAR BEAM EPITAXY
PHOTOCONDUCTIVITY
PROBABILITY
RECOMBINATION
SEMICONDUCTOR MATERIALS
SILICON
SILICON COMPOUNDS
X-RAY DIFFRACTION