Dark current reduction in AlxGa1−xAs-GaAs heterojunction diodes

Abstract

The addition of a thin, high band‐gap P(N)‐type Al_xGa_1−xAs layer into a conventional Al_yGa_1−yAs‐GaAs N‐p (P‐n) heterojunction is found to significantly reduce the 2kT recombination current, thereby permitting the bulk diffusion current to dominate at current densities as low as ∼10⁻⁵ A/cm². Experiment indicates that the 2kT current is due to surface‐recombination processes and originates in a very narrow region near the p‐n junction, presumably due to the small minority‐carrier surface‐diffusion length.