Abstract
First principle calculations of amorphous hydrogenated silicon Schottky barrier and p-i-n diodes' current-voltage characteristics have revealed an interesting relation between the observed quality factor and the composition of the diode current. The diode current consists of two components: (1) The drift/diffusion current, J <sub>D</sub> , which is virtually independent of carrier recombination mechanism, and (2) the recombination current J <sub>R</sub> . Each component has a characteristic value of the quality factor, β (inverse slope of semilog J-V plot): β<1.1 for J <sub>D</sub> and β≥1.6 for J <sub>R</sub> . In addition, the relative magnitudes of the two components vary with the device thickness, the density of localized states, and the surface barrier potential. The difference in the quality factors observed in Schottky barriers and in p-i-n diodes can be interpreted as an indication of change in the dominant component from J <sub>D</sub> to J <sub>R</sub> , due to a larger surface potential in the latter device.