Picosecond Photomodulation Studies of Carrier Trapping in a-Si:H
Subnanosecond trapping in gap states of photogenerated carriers in doped, compensated and undoped a-Si:H, and a—Si:H/a—SiNx:H multilayer structures, was studied by the picosecond pump and probe technique. In undoped a-Si:H the photoexcited carriers are trapped in band-tail states and in compensated a-Si:H in impurities introduced by doping. In singly doped a-Si:H the photoexcited majority carriers are trapped in impurities while the minority carriers are trapped in charged dangling bonds introduced by doping. In a—Si:H/a—SiNx:H superlattices photocarriers are trapped in interface related defects. The transport dynamics of the trapping process is in all cases dispersive.
KeywordsMinority Carrier Deep Trap Photogenerated Carrier Amorphous Semiconductor Shallow Trap
Unable to display preview. Download preview PDF.
- 2.Z. Vardeny and J. Tauc in Semiconductors Probed by Ultrafast Laser Spec troscopy (R. R. Alfano, ed.) Vol. 2, Academic Press, N.Y., (1984), p. 23.Google Scholar
- 4.J. Tauc, in Semiconductors and Semimetals Vol. 21B, (V. I. Pankove, ed.) Academic Press, N.Y., (1984) p. 299.Google Scholar
- 13.A. M. Johnson in Ref. 2, p. 1.Google Scholar
- 16.J. Strait, Ph.D. Thesis, Brown University (1984).Google Scholar
- 18.W. B. Jackson, C. Doland and C. C. Tsai, Phys. Rev. B (Rapid Commun.), in press.Google Scholar
- 19.H. T. Grahn, H. A. Stoddart, T. Zhou, Z. Vardeny, J. Tauc and B. Abeles, Proceedings of the 18th Int. Conf. on Physics of Semiconductors, Stockholm (August 1986), to be published.Google Scholar
- 21.D. Monroe, Sol. State Commun., in press.Google Scholar
- 24.B. Abeles and T. Tiedge, Phys. Rev. Lett. 51, 2003 (1983).Google Scholar
- 25.C. B. Roxlo, B. Abeles and T. Tiedge, Phys. Rev. Lett. 52, 1994 (1981).Google Scholar