Research on amorphous carbon (a-C) to date has focused on the distinction between the sp(2) and sp(3) phases and understanding the properties on the basis of the sp(2)-C bonded component. Recently, sufficient information on the sp(2) -bonded clusters and nanoforms of carbon has helped to identify the importance of sp(2)-C over sp(3)-C, especially in transport properties and encouraged many groups to exploit this knowledge for device design. However, at present, few studies dedicated purely to understanding the transport properties and electronic structure of the family of a-C films as a whole is available. In this paper, we try to identify the key issues in using a-C as an unconventional semiconducting material and try to elaborate on how to overcome these hurdles in order to utilize this extremely versatile material for active device fabrication. (c) 2004 Elsevier B.V. All rights reserved.