New High-Speed a-Si/c-Si- and a-SiC/c-Si-Based Switches

The electrical and optical characteristics of the new high-speed Al/a-Si/c-Si(p)/c-Si(n+)/Al and Al/a- SiC/c-Si(p)/c-Si(n+)/Al optically controlled switches are presented in this paper. These switches exhibit the lowest ever reported values of rise and fall times, for this kind of switches, of about 3ns. They also exhibit a temperature and light reversibly controlled forward breakover voltage (VBF), together with high values of light triggering sensitivity

The Structure Of a-Si(1-X)Sn(X)H Thin Films

The doping of a-Si:H with Sn is known to modify the electrical and optical properties of the material. The optical band gap decreases as the doping level is increased, however, there is no insulator-metal transition of the type observed, for example, when transition metals are used as dopants. In order to increase the understanding of the conductivity processes that occur in a-Si:metal:H alloys we have measured the atomic scale structure of a series of a-Si(1-x)Sn(x):H thin-films using EXAFS. Samples were prepared by RF reactive co-sputtering and both Si and Sn K-edge EXAFS examined. The results indicate that the Sn atoms are substituted randomly into the a-Si tetrahedral random network. Both Si and Sn atoms retain fourfold co-ordination over the composition range studied (0-less-than-or-equal-to-x-less-than-or-equal-to-0.18). In contrast to results obtained using transition metal dopants there is no local modification of the tetrahedral random network

Crystalline Silicon Thin-Film Solar Cells via High-Temperature and Intermediate-Temperature Approaches

10.1002/9780470974704.ch11Handbook of Photovoltaic Science and Engineering452-48