Computer simulation of amorphous-silicon charge-coupled devices

The electron dynamics in amorphous-silicon charge-coupled devices have been investigated numerically by taking into account tail states and deep defect states in the energy gap of the active amorphous-silicon layer. It has been revealed that the deep states far from the conduction band have a great influence on electron-transfer characteristics and that a field-free region caused by metallic electrodes prevents quick drift motion of electrons. Based on those numerical results, a novel device structure with a narrow channel has been proposed. Calculated results on device efficiency agree well with the experimental data of M. Matsumara et al. (1987), assuming a deep-state density of 2×10¹⁶ cm^-4/eV