Reproducible lowhyphen;resistance contacts tophyphen;type CdTe single crystals have been made by diffusion of Li into the CdTe surface before evaporation of Au as the contact metal. Diffusion produces a surface hole density of about 1019cmminus;3at room temperature; this results in a contact resistivity of the order of 0.01 OHgr;thinsp;cm2, the lowest value reported to date forphyphen;type CdTe. The high diffusivity of Li results in a degradation of the contacts even at room temperature, with the degradation rate critically dependent on the temperature used for Li diffusion. The optimum temperature appears to be about 280thinsp;deg;C; contacts formed on surfaces diffused with Li at this temperature show a contact resistivity of 0.025 OHgr;thinsp;cm2after 5 months.
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