A switching device based on a-Si:H n-i-/spl delta/p-i-n stacked structure: modeling and characterization

A new two-terminal switching device based on an a-Si:H n-i-/spl delta/p-i-n symmetrical structure is investigated. The current through the device arises from thermionic emission of electrons over the triangular barrier lowered by the applied voltage. The key role of the thickness and of the doping level of the central /spl delta/p layer on the electrical behavior of the device is analyzed in detail by a numerical model. The current-voltage characteristic of an optimized device exhibits an ON/OFF current ratio, taken at 3 and 1 V, respectively, of six orders of magnitude with a nonlinearity factor /spl eta/=3.7.