Optical Studies of Nonequilibrium Carrier Dynamics in Highly Excited 4H-SiC Epitaxial Layers


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We applied picosecond four-wave mixing technique to investigate carrier diffusion and recombination in n-type 4H-SiC epilayers. The dependence of bipolar diffusion coefficient D on photocarrier density was measured in range from ~ 1017 to ~ 1020 cm-3. We determined a decrease of D value from 3.4 to 2.2 cm2/s with increase of the photoexcitation level in range from ~ 1017 to ~ 1019 cm-3, and found its increase up to 3.8 cm2/s at carrier density above 1020 cm-3. Auger recombination governed decrease of carrier lifetime from 11 ns at ~ 1017 cm-3 to 1.8 ns at ~ 1020 cm- 3 has also been observed.



Materials Science Forum (Volumes 483-485)

Edited by:

Dr. Roberta Nipoti, Antonella Poggi and Andrea Scorzoni




K. Neimontas et al., "Optical Studies of Nonequilibrium Carrier Dynamics in Highly Excited 4H-SiC Epitaxial Layers", Materials Science Forum, Vols. 483-485, pp. 413-416, 2005

Online since:

May 2005




[1] B.J. Baliga: Power Semiconductor Devices (PWS Publishing Company, 1995).

[2] C. Brylinski: Proceedings European Space Components Conference (ESCCON 2000, 21-23 March 2000, 217-224(2000).

[3] P. Grivickas, J. Linnros and V. Grivickas: Mater. Sci. Forum Vol. 338-342 (2000), p.671; P. Grivickas: Optical Studies of Carrier Transport and Fundamental Absorption in 4H-SiC and Si (Dissertation: ISSN 0284-545, Stockholm, 2004).

DOI: https://doi.org/10.4028/www.scientific.net/msf.338-342.671

[4] A. Ellison, J. Zhang, A. Henry, E. Janzen: J. Crystal Growth Vol. 236 (2002), p.225.

[5] H. J. Eichler, P. Gunter, D. W. Pohl: Laser-induced dynamics gratings (Optical sciences 50, 114-119, 1986).

[6] We note, that non-equilibrium carrier concentrations given in Fig. 3 and Fig. 4 at 266 nm excitation correspond to initial carrier densities (∆t = 0) at a very surface of the excited sample.

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