ETHYLIODIDE N-TYPE DOPING OF HG1-XCDXTE (X=0.24) GROWN BY METALORGANIC MOLECULAR-BEAM EPITAXY

Conductive n-type Hg1-xCdxTe epitaxial layers with x=0.24 were grown b y metalorganic molecular beam epitaxy using iodine doping. Ethyliodide was chosen as the dopant precursor based on previous results obtained for CdTe. The low-temperature (20 K) electron concentration increased from an undoped level of similar to 10(15) cm(-3) to 5x10(18) cm(-3) for ethyliodide flow rates from 10(-4) to 10 sccm. High electron mobil ities were measured and secondary ion mass spectrometry measurements i ndicated a high degree of electrical activity. These results demonstra te that iodine is a highly effective n-type dopant for long-wavelength HgCdTe alloys and device structures. (C) 1994 American Institute of P hysics.