| Popis: |
We report on the electrical and electro-optical properties of n- and p-type (211)B mercury cadmium telluride grown by molecular beam epitaxy for Cd composition ∼ 0.22. Grown layers show excellent structural qualities with DCRC FWHM of 25-40 arcsec. However, in the unintentionally doped layers a complex picture of transport characteristics were observed. Indium doped layers grown on Nippon Mining substrates show excellent Hall characteristics and minority carrier lifetimes down to 1 X 10 15 cm -3 doping levels. But, when the net doping level falls below ∼ 2 X 10 15 cm -3 , the measured lifetime data indicates Shockly-Read (SR) recombination centers. We believe that these SR levels are related to Hg vacancies. Also, arsenic is being investigated as a p-type dopant through a new approach called planar doping for MBE-HgCdTe. The obtained results are very promising. During the growth process using this method, the incorporated arsenic can be electrically activated at a temperature not exceeding 250°C. |
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