Effect of lithium ion irradiation on the transport and optical properties of Bridgman grown n-type InSb single crystals

Single crystal (100) wafers of n-InSb were implanted with 50 MeV Li3+ ions at various fluences ranging from 1010 to 1014ions/cm2 at room temperature. Investigations of the optical, electrical, and structural properties of the as-grown, irradiated, annealed wafers were carried out by infrared and Raman spectroscopies, Hall measurements, and high resolution x-ray diffraction (HRXRD). In the case of samples irradiated with an ion fluence of 1.6 x 1014ions/cm2, electrical measurements at 80 K reveal that there is a decrease in carrier concentration from 8.5 x 1015 (for unirradiated) to 1.1 x 1015/cm3 and an increase in mobility from 5.4 x 104 to 1.67 x 105cm2/Vs. The change in carrier concentration is attributed to the creation of electron trap centers induced by ion beam irradiation and the increase in mobility to the formation of electrical inactive complexes. Nevertheless, even with the irradiation at 1.6 x 1014ions/cm2 fluence the crystalline quality remains largely unaffected, as is seen from HRXRD and Raman studies. copyright 2001 American Institute of Physics