The preparation of conductive ZnS films by using MBE with a single effusion source

doi:10.1016/0022-0248(84)90141-6

Journal of Crystal Growth

Volume 67, Issue 1, June 1984, Pages 125-134

https://doi.org/10.1016/0022-0248(84)90141-6 Get rights and content

Abstract

We have successfully grown ZnS films on GaAs and GaP substrates by using an MBE technique with a single effusion source of ZnS compounds. The epitaxial ZnS films grown on the (001) face of the substrates have a cubic structure free from twins and exhibit n-type conductivity with a maximum carrier concentration of ≈ 2x10¹⁴ cm^-3 and a maximum Hall electron mobility of ≈ 90 cm²/Vh.s. This was realized under the optimum growth temperature of ≈ 240°C. Their luminescence spectra show that two kinds of deep level luminescence, divided into a high energy blue broad emission band and a low energy red broad emission band, are dominant. Their major origin may be attributed to the Cu impurity which is incorporated during growth by evaporation of the impurities contained in the source materials. On the other hand, epitaxial ZnS films grown on the $(111)$ face of the substrates contain {111} twins 180° rotated about the axis normal to the grown layer surface so that they exhibit a resistivity greater than 10⁴ Ω cm.

References (19)

H. Kukimoto et al.
J. Phys. Chem. Solids
(1968)
S. Fujita et al.
J. Crystal Growth
(1979)
M. Kitagawa et al.
J. Crystal Growth
(1978)
H.M. Manasevit
J. Crystal Growth
(1972)
P.J. Dean et al.
J. Crystal Growth
(1982)
T. Yao et al.
J. Crystal Growth
(1981)
A.Y. Cho et al.
Molecular Beam Epitaxy, Progress in Solid State Chemistry
(1975)
H. Samelson
J. Appl. Phys.
(1961)
D.K. Wickenden et al.

There are more references available in the full text version of this article.

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The preparation of conductive ZnS films by using MBE with a single effusion source

Abstract

J. Phys. Chem. Solids

J. Crystal Growth

J. Crystal Growth

J. Crystal Growth

J. Crystal Growth

J. Crystal Growth

Molecular Beam Epitaxy, Progress in Solid State Chemistry

J. Appl. Phys.