SPACE-CHARGE ANALYSIS OF SI N(-I STRUCTURES WITH APPLICATION TO FAR-INFRARED DETECTORS())

The operation mechanism of the Si homojunction interfacial workfunctio n internal photoemission far-infrared detector is based on internal ph otoemission occurring at the interfacial barrier between a heavily dop ed absorber/emitter layer and an intrinsic (i) layer. Due to the free carrier ''spill over'' from the emitter to the i layer, a space charge region is created near the interface, which was neglected in the prev ious detector performance analyses. In this paper, we calculate the di stributions of free electron concentration, ionized donor concentratio n, potential barrier, and electric field in the space charge region, f or an n(+)-i structure with a thick i layer at low temperatures, by nu merically solving the drift-diffusion equation. The dependence of thes e distributions on applied bias, temperature, and i layer doping level , are investigated. By using these results, the previous experimental results obtained from commercial Si p-i-n diodes can be well explained .