Effect of Ge Incorporation on Hydrogenated Amorphous Silicon Germanium Thin Films Prepared by Plasma Enhanced Chemical Vapor Deposition

Abstract:

Hydrogenated amorphous silicon germanium thin films (a-SiGe:H) were prepared via plasma enhanced chemical vapor deposition (PECVD). By adjusting the flow rate of GeH4, a-SiGe:H thin films with narrow bandgap (Eg) were fabricated with high Ge incorporation. It was found that although narrow Eg was obtained, high Ge incorporation resulted in a great reduction of the thin film photosensitivity. This degradation was attributed to the increase of polysilane-(SiH2)n, which indicated a loose and disordered microstructure, in the films by systematically investigating the optical, optoelectronic and microstructure properties of the prepared a-SiGe:H thin films via transmission, photo/dark conductivity, Raman spectroscopy, and Fourier transform infrared spectroscopy (FTIR) measurements. Such investigation provided a helpful guide for further preparing narrow Eg a-SiGe:H materials with good optoelectronic properties.

• Periodical: Advanced Materials Research (Volume 569)
• Pages: 27-30
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.569.27
• Online since: September 2012
• Authors: Bao Jun Yan, Lei Zhao, Ben Ding Zhao, Jing Wei Chen, Hong Wei Diao, Guang Hong Wang, Wen Jing Wang
• Keywords: a-SiGe:H, Bandgap Adjustment, Ge Incorporation, PECVD, Photosensitivity

References

[1] D. Carlson, C. Wronski: Appl. Phys. Lett. Vol. 28 (1976), p.671.

[2] J. Joo: Thin Solid Films Vol. 519 (2011), p.6892.

[3] B.J. Yan, G.Z. Yue, L. Sivec, et al.: Appl. Phys. Lett. Vol. 99 (2011), art. 113512.

[4] A. Lambertz, T. Grundler, F. Finger: J. Appl. Phys. Vol. 109 (2011), art. 113109.

[5] B.J. Yan, J.M. Owens, C.S. Jiang, et al.: Mater. Res. Soc. Symp. Proc. Vol. 862 (2005), art. A23. 3. 1.

[6] J. Yang, A. Banerjee, and S. Guha: Appl. Phys. Lett. Vol. 70 (1997), p.2975.

[7] J. Tauc, R. Grigorovici, A. Vancu: Phys. Status Solidi B Vol. 15 (1966), p.627.

[8] S. Tsuda, H. Tarui, H. Haku, et al.: J. Non-Cryst. Solids Vol. 77-78 (1985), p.845.

[9] Y.H. Chen, H.Y. Fang, C.M. Yeh: J. Non-Cryst. Solids Vol. 357 (2011), p.1.

[10] Z. Tang, W. Wang, D. Wang, et al.: J. Alloys Comp. Vol. 504 (2010), p.403.

[11] J. Tauc, R. Grigorovici, A. Vancu: Mat. Res. Bull. Vol. 3 (1968), p.37.

[12] L. Zhao, B.J. Yan, B.D. Zhao, et al.: Adv. Mater. Res. Vols. 457-458 (2012), p.663.

[13] M. Cardona: Phys. Status Solidi B Vol. 118 (1983), p.463.

[14] Y.P. Chou, S. Ch. Lee : J. Appl. Phys. Vol. 83 (1998), p.4111.