The free carrier concentration and compensation ratio of unintentionally doped InAs were reliably determined by evaluating the conduction characteristics of as-grown and hydrogenated epilayers. The free carrier concentration has also been obtained using steady-state capacitance measurements performed on p-i-n diodes fabricated using various growth conditions. The influence the growth temperature has on the electrical characteristics of unintentionally doped InAs thin films is presented. (c) 2011 Elsevier B.V. All rights reserved.