Abstract
This paper describes studies of the microstructure and optical absorption edge of films of a-Si: H and a-SiNx: H alloys (x=0.0–0.72), obtained by decomposing gas mixtures in an rf glow discharge. For the a-Si: H films, the gas mixture was monosilane diluted by hydrogen, for the a-SiNx: H alloys it was SiH4+NH3. Structurally nonuniform films with “device-quality” optoelectronic characteristics were obtained when the rates of growth were increased (to 8 Å/s). Atomic force microscopy and infrared absorption spectroscopy are used to identify a characteristic feature of the microstructures of these films: the presence of islets ∼500 Å in diameter, whose boundaries are formed by clusters of hydrogen atoms (in the case of a-Si: H) or of hydrogen and nitrogen (in the case of a-SiNx: H). In this case the optical band gap of a-Si: H (a-SiNx: H) is determined by the concentration of SiH (SiN) bonds in the interior of the islets and is not sensitive to changes in the content of hydrogen (nitrogen) at their boundaries. This result is explained by a quantum-well model which takes into account the characteristic sizes of the microstructures formed by hydrogen or nitrogen atoms.
Similar content being viewed by others
References
G. D. Cody, Semicond. Semimet. 21B, 11 (1984).
M. B. Schubert, H.-D. Mohring, E. Lotter, and G. H. Bauer, IEEE Trans. 36, 2863 (1989).
A. P. Sokolov, A. P. Shebanin, O. A. Golikova, and M. M. Mezdrogina, J. Non-Cryst. Solids 137/138, 99 (1991).
J. Robertson, Philos. Mag. 63, 47 (1991).
M. H. Brodsky, Solid State Commun. 36, 55 (1980).
A. A. Klochikhin, Phys. Rev. B 52, 979 (1995).
S. K. O’Leary, S. Zukotinsky, and J. M. Pierz, J. Appl. Phys. 78, 4282 (1995).
B. G. Budagyan, A. Aivazov, A. Yu. Sazonov, A. A. Popov, and A. E. Berdnikov, Mater. Res. Soc. Spring Meeting (San Francisco, USA, 1997).
A. A. Langford, M. L. Fleet, B. P. Nelson, W. A. Lanford, and N. Maley, Phys. Rev. B 45, 367 (1992).
S. Chattopadhay, S. N. Sharma, R. Banarjee, D. M. Bhusari, S. T. Kshirsagar, Yan Chen, and D. L. Wiliamson, Appl. Phys. Lett. 76, 5208 (1994).
J. W. Osenbach and W. R. Knolle, J. Appl. Phys. 60, 1408 (1986).
G. Lucovsky, J. Yang, S. S. Chao, J. E. Tyler, and W. Czubatyj, Phys. Rev. B 28, 3234 (1983).
E. Bustarret, M. Bensouda, M. C. Habrard, J. C. Bruyere, S. Pouline, and S. C. Gujrathi, Phys. Rev. B 38, 8171 (1988).
B. G. Budagyan, A.A. Aivazov, and A. Yu. Sazonov, Physica B 193, 195 (1994).
J. M. Marshall, R. A. Street, and M. J. Thompson, Philos. Mag. B 54, 51 (1986).
J. Baum, K. K. Gleason, A. Pines, A. N. Garroway, and J. A. Reimer, Phys. Rev. Lett. 56, 1377 (1986).
L. D. Landau and E. M. Lifshitz, Quantum Mechanics: Nonrelativistic Theory (3rd ed. Pergamon Press, Oxford, 1977) [Russ. orig. Nauka, Moscow, 1989].
Author information
Authors and Affiliations
Additional information
Fiz. Tekh. Poluprovodn. 32, 531–536 (May 1998)
Rights and permissions
About this article
Cite this article
Budagyan, B.G., Aivazov, A.A., Stryakhilev, D.A. et al. A quantum-well model and the optical absorption edge in structurally nonuniform a-Si:H-based alloys. Semiconductors 32, 473–478 (1998). https://doi.org/10.1134/1.1187421
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1134/1.1187421