Abstract
Using the electroreflectance method space charge layers on crystals of different conductivities have been identified. The space charge layers were formed by adsorption of oxygen or atomic hydrogen. The limit of sensitivity required the irradiation with 5×1013 photons/cm2×sec of band gap energy. After exposure to atomic hydrogen all samples showed accumulation layers. With a partial pressure of oxygen above 350 mm Hg crystals of high conductivity (σ=47 ohm−1 cm−1) exhibit depletion layers, which change into accumulation layers, if the partial pressure is reduced below the limit. Crystals of a lower conductivity (σ=10−3–10−1 ohm−1 cm−1) show accumulation layers up to the highest applied oxygen pressure of 760 mm Hg. The phenomena are attributed to a dynamical equilibrium between adsorption and photo-desorption of oxygen. This equilibrium depends on oxygen pressure and free carrier concentration. By comparing a calculated curve with the experimental results the value of 3.31 ev is obtained for the energy gap, light polarized perpendicular to thec-acis.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Herrn Prof. Dr. G.Heiland danke ich herzlich für seine Anregungen bei der Durchführung dieser Arbeit und für die Möglichkeit, die Messungen in seinem Institut durchzuführen.
Herrn Priv.-Doz. Dr. W.Mönch und Herrn Dr. M.Henzler danke ich für ihre stete Bereitschaft zu Diskussionen.
Rights and permissions
About this article
Cite this article
Hoffmann, B. Untersuchung von Raumladungsschichten an Zinkoxid-Oberflächen mit Hilfe der Elektroreflexion. Z. Physik 219, 354–363 (1969). https://doi.org/10.1007/BF01395532
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF01395532