ELECTRICAL-PROPERTIES OF HG1-XCDXTE GROWN BY LOW-TEMPERATURE METALORGANIC VAPOR-PHASE EPITAXY

Electrical properties of Hg1-xCdxTe layers grown by low-temperature metalorganic vapor phase epitaxy at 275 degrees C have been studied. Substrates used were (100) GaAs. The precursors used were dimethylcadmium (DM Cd), elemental mercury, and ditertiarybutyltelluride. Cadmium composition a: of the layers was controlled from 0 to 1 by DMCd flow. Van der Pauw measurements were carried out in the temperature range from 25 to 300 K. For HgTe layers, typical 80 K electron concentration and Hall mobility of 4.4 x 10(16) cm(-3) and 8.0 x 10(4) cm(2)/V . s were obtained. For CdTe, 300 K hole concentration and hole Hall mobility of 1.2 x 10(15) cm(-3) and 6.5 x 10(1) cm(2)/V . s were obtained. In the intermediate Cd composition region of x=0.44, 80 K electron concentration of 8.0 x 10(15) cm(-3) and Hall mobility as high as 7.4 x 10(3) cm(2)/V . s were also obtained. The experimental mobilities were explained by polar-optical phonon and alloy scattering.