Measurements of the conductivity and the Hall effect of single crystals were performed on zinc oxide samples after a thermal diffusion of indium and copper with different time periods. Single crystals of ZnO were growth by hydrothermal method and annealed previously to diffusion process. Diffusion was carried out in ZnO at 1000C in N2 atmosphere for 3, 6 and 15h. Hall effect measurements were carried out using the Van der Pauw configuration with a current of 1mA and a magnetic field of 0.37T at room temperature. Results showed an increase in donor concentration from 4.6 x 1014 to 1.15 x 1017/cm3 when In was diffused and up to 9.9 x 1015/cm3 when Cu was introduced in ZnO. Mobility decreased from 134.9 (undoped ZnO) to 44.7cm2/Vs, in In-doped, and 101.9cm2/Vs, in Cu-doped. Resistivity decreased with time from 1.29 x 102Ωcm to 1.26Ωcm and 6.25Ωcm, in the same order as described. Based on measurements, introduction of indium was faster than copper and the higher concentration of donors was result of substitution of Zn by an ion with a different valence. This was a relative simple method to control the conductivity and donor concentration in single crystals of ZnO.

Hall Effect and Conductivity in Zinc Oxide (ZnO) Doped by Thermal Diffusion of Indium and Copper. Juárez-Diaz, G., Martínez, J., García-Cruz, M.L., Peña-Sierra, R., García, J.A., Pacio, M.: Physica Status Solidi C, 2010, 7[3-4], 957-9