The Density-of-State Distribution in Undoped a-Si:H and a-SiGe:H Determined by Heterojunctions with c-Si


A novel technique has been proposed for determining the density-of-state (DOS) distribution in the mobility gap of highly resistive amorphous semiconductors, using amorphous/crystalline heterojunction structures. This technique has been tested and applied on undoped a-Si:H and a-SiGe:H films, covering the optical gap (E0 ) range of 1.30 to 1.76 eV. For undoped a-Si:H with E0 =1.76 eV, the peak of the midgap DOS distribution has been locatedst 0.85 eV below the conduction band edge, EC , with a value of 5.6×1015 cm-3 eV-1 . For undoped a-SiGe:H (E0 =1.55 eV) the same has been obtained 0.71 eV below EC with a magnitude of 7.9×1016 cm-3 eV-1. Those midgap states have been found to be correlated with singly-occupied dangling bonds.

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  1. 1.

    S. Yamasaki, Philos. Mag. B 56, 79 (1987).

    CAS  Article  Google Scholar 

  2. 2.

    H. Okushi, Philos. Mag. B 52, 33 (1985).

    CAS  Article  Google Scholar 

  3. 3.

    K. D. Mackenzie, J. R. Eggert, D. J. Leopold, Y. M. Li, S. Lin, and W. Paul, Phys. Rev. B 31, 2198 (1985).

    CAS  Article  Google Scholar 

  4. 4.

    A. Skumanich, A. Frova, and N. M. Amer, Solid State Commun. 54, 597 (1985).

    CAS  Article  Google Scholar 

  5. 5.

    S. Aljishi, Z E. Smith, D. Slobodin, J. Kolodzey, V. Chu, R. Schwarz, and S. Wagner in Materials Issues in Amorphous-Semiconductor Technology, edited by D. Adler, Y. Hamakawa, and A. Madan (Mater. Res. Soc. Proc. 70, Pittsburgh, PA 1986) pp. 269–274.

  6. 6.

    Y. Tsutsumi, S. Sakata, K. Abe, Y. Nitta, H. Okamoto, and Y. Hamakawa, J. Non-Cryst. Solids 97&98, 1063 (1987).

    Article  Google Scholar 

  7. 7.

    H. Matsuura, T. Okuno, H. Okushi, and T. Tanaka, J. Appl. Phys. 55, 1012 (1984).

    CAS  Article  Google Scholar 

  8. 8.

    H. Matsuura, submitted to J. Appl. Phys.

  9. 9.

    A. Matsuda, M. Koyama, N. Ikuchi, Y. Imanishi, and K. Tanaka, Jpn. J. Appl. Phys. 25, L54 (1986).

    CAS  Article  Google Scholar 

  10. 10.

    H. Matsuura and H. Okushi, J. Appl. Phys. 62, 2871 (1987).

    CAS  Article  Google Scholar 

  11. 11.

    S. Aljishi, V. Chu, Z E. Smith, D. S. Shen, J. P. Conde, D. Slobodin, J. Kolodzey, S. Wagner, J. Non-Cryst. Solids 97&98, 1023 (1987).

    Article  Google Scholar 

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Correspondence to Hideharu Matsuura.

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Matsuura, H., Tanaka, K. The Density-of-State Distribution in Undoped a-Si:H and a-SiGe:H Determined by Heterojunctions with c-Si. MRS Online Proceedings Library 118, 647 (1988).

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