Quantum Size Effects in a Si:H Films Prepared by PECVD with Different Hydrogen-Diluted Silane

Abstract:

Quantum size effect (QSE) comprises a novel phenomenon where structural, mechanical, thermal, electronic and optical properties of solids are affected by the reduction in particle size. Size-dependent properties in semiconductors and dielectrics come into play especially by making one (thin films) or more (quantum wires and dots) dimensions of a sample very small, particularly going from micro to nano-dimensions. One or more dimensional QSE is accompanied with an increase of the light absorption and the blue-shift of the optical band-gap due to a creation or reduction of the crystallite sizes having different dielectric constants (relative permitivity). Understanding the nature of the size-induced properties is of fundamental importance for advanced technological applications. The size-dependent band-gap makes a material attractive for optical absorption-based applications. In this work, a-Si:H films different in thickness were prepared by PECVD technology using different hydrogen-diluted silane. One-dimensional QSE (when film thickness decreased) and three-dimensional QSE (when due to a high hydrogen-silane dilution the nano-crystalline structure of the films appeared) were observed.

• Periodical: Advances in Science and Technology (Volume 74)
• Pages: 137-142
• DOI: https://doi.org/10.4028/www.scientific.net/AST.74.137
• Online since: October 2010
• Authors: Lucie Prušaková, V. Vavruňková, M. Netrvalová, J. Müllerová, P. Šutta
• Keywords: Amorphous Hydrogenated Silicon, Optical Band-Gap Blue-Shift, Quantum Size Effect

References

[1] C. Q. Sun, Progress in Solid State Chemistry, 55, 1 (2007).

[2] S. Nihonyanagi, K. Nishimoto, Y. Kanemitsu, J. Non-Cryst. Solids, 299–302, 1095 (2002).

[3] S. Nomura et al.: Phys. Rev. B, 59, 10309 (1999).

[4] Müllerová, J. - Vavruňková, V. - Šutta, P.: Optical absorption of PE CVD deposited thin hydrogenated silicon in light of ordering effects. Cent. Eur. J. Phys. 7(2), 315 (2009).

[5] Jellison, G.E. Jr., Modine, F.A., Parametrization of the optical functions of amorphous materials in the interband region, Appl. Phys. Lett. 69, 371 – 373 (1996) and erratum Appl. Phys. Lett. 69, 2137 (1996).

DOI: 10.1063/1.118155

[6] Mullerová J., Prusakova L., Netrvalova M., Vavrunkova V., Sutta P.: A study of optical absorption in amorphous hydrogenated silicon thin films of varied thicknesses, Applied Surface Science, In Press (2010).

DOI: 10.1109/miel.2010.5490488

[7] G.E. Jellison, F.A. Modine, Appl. Phys. Lett. 69, 3, 1996, 371.

[8] Erratum Appl. Phys. Lett. 69, 14, 1996, 2173.

[9] A.S. Ferlauto, G. M. Ferreira, J. M. Pearce, C.R. Wronski, R.W. Collins, J. Appl. Physics, 92, 5, 2002, 2424.

[10] P. Chaudhuri et al.: J. Non-Crystall. Solids, 338–340, 236 (2004).

[11] Y. Kayanuma, H. Momiji: Incomplete confinement of electrons and holes in microcrystals, Rapid Communications, 41, 14, 1990, 10 261.

DOI: 10.1103/physrevb.41.10261