Transport properties in gallium doped CdTe MOVPE layers

Hall measurements have been performed on gallium-doped n-type CdTe metalorganic vapor phase epitaxy layers between 25 and 300 K. The Hall coefficient and mobility data could be better explained assuming a singly ionized donor model. The ionization energy of the isolated shallow donor is estimated to be about 15.3 meV below the conduction band. The analysis also showed that the layers are not heavily compensated. Low-temperature mobilities as high as 3000 cm(2)/V . s are obtained. The model of scattering by optical phonon, acoustical phonon, ionized and neutral impurity satisfactorily accounts for the mobility data, supporting the low compensation ratio obtained from the carrier concentration analysis. The results demonstrate that high-quality n-type layers can be obtained using gallium.