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 10(10) to 10(14) ions/cm(2) at room temper ature. 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 diff raction (HRXRD). In the case of samples irradiated with an ion fluence of 1 .6x10(14) ions/cm(2), electrical measurements at 80 K reveal that there is a decrease in carrier concentration from 8.5x10(15) (for unirradiated) to 1 .1x10(15)/cm(3) and an increase in mobility from 5.4x10(4) to 1.67x10(5) cm (2)/V s. The change in carrier concentration is attributed to the creation of electron trap centers induced by ion beam irradiation and the increase i n mobility to the formation of electrical inactive complexes. Nevertheless, even with the irradiation at 1.6x10(14) ions/cm(2) fluence the crystalline quality remains largely unaffected, as is seen from HRXRD and Raman studie s. (C) 2001 American Institute of Physics.