Field emission from amorphous semiconductors

Amorphous semiconductors such as a-C:H and a-Si:H deposited via conventiona l commercially available plasma enhanced chemical vapour deposition systems (PECVD) have been shown to be capable of electron emission at low threshol d fields. Using PECVD it is possible to produce 'mirror like' thin films ov er large areas which if deposited under optimised conditions of film thickn ess and dopant content can produce good field electron emission characteris tics. This paper will discuss the results of different experiments, which s how that by a suitable choice of substrates, deposition and post-deposition treatments it is possible to optimise the threshold electric field. The ro le of defects on the electron emission properties of the films is discussed and the electron emission process will be discussed in terms of a space-ch arge induced emission mechanism. (C) 2001 Elsevier Science Ltd. All rights reserved.