Gas source iodine n-type doping of molecular beam epitaxially grown CdTe

Highly conductive n-type CdTe films were grown by molecular beam epitaxy by iodine doping, utilizing ethyliodide as the dopant precursor. The room-temperature electron concentration increased from 8×1016 to 3×1018 cm−3 for dopant flow rate from 10−5 to 10−2 sccm and the films exhibited very high electron mobilities. The structural and optical properties were determined by x-ray double crystal rocking curve and photoluminescence measurements. Secondary ion mass spectroscopic analysis indicated a high degree of electrical activity, and sharp dopant profiles. These results demonstrate that iodine is highly effective for the n-type doping of CdTe.