Double Injection in Semiconductors

A new model for double injection in high‐resistivity semiconductors, containing recombination centers, is proposed. The negative resistance is associated with the presence of a saturated trap region near the minority‐carrier injecting contact, which extends toward the opposite contact for increasing current. By using the regional approximation method, an analytical current‐voltage characteristic is obtained which describes both the prebreakdown and negative‐resistance regime. The present theory shows that the deviation from the quadratic J‐vs‐V behavior in the prebreakdown regime depends upon the interelectrode separation and gives a good fit for the prebreakdown characteristic of Au‐GaP diodes. The theoretical breakdown voltage decreases with increasing thermal free‐carrier concentration, and good quantitative agreement is found for the experimental results for GaP and InSb double‐injection diodes.