Hall effect measurements on ZnO accumulation layers

Publisher Website
Google Scholar
Abstract
The surface Hall effect on clean cleaved polar and prism faces has been measured between 90 and 200K. Accumulation layers ranging from surface electron densities Delta N=106 to 3*1014 cm-2 were generated by hydrogen discharge and by illumination. The derived mobilities cover the range between 2 and 3000 cm2 V-1 s-1. At low surface electron densities a modulated structure apparently correlated with surface donor density was observed. Illumination of the Zn face induces a nearly complete screening of bulk impurities within the space charge layer resulting in surface mobilities exceeding the bulk values. At higher densities an activated mobility, dependent on surface preparation, appeared on all three faces. For interpretation, several models of disorder are discussed. Only above Delta N=1014 cm-2 was surface roughness scattering observed. In this region the mobility can be varied by different pretreatments.

This publication has 17 references indexed in Scilit: