Acceptor levels of high degeneracy in ZnO derived from combined space charge capacitance and hall effect data

The trap distribution in the bulk of ZnO crystals is studied by combined measurements of space-charge capacitance at the electrolyte/ZnO interface and of conductivity and Hall effect. The former yield the density and effective energy of the dominant acceptor levels, while the latter determine their actual energy position. The two types of data enable a rather accurate determination of the degeneracy factor of the acceptors in the samples studied (6 ± 1), information that is very difficult to gain by any other means.