Dark Current Mechanism in Bulk GaInNAs Lattice Matched to GaAs

The reverse-bias current-voltage characteristics of a series of Ga_1-xln_xN_yAs_1-y diodes with bandgap of between 0.87 and 1.04 eV are reported. At low bias, diffusion and generation-recombination currents are dominant at high and low temperatures, respectively. At high reverse bias, the dark current is insensitive to changes in temperature, which is indicative of tunneling current mechanisms. We also observe an exponential dependence of the dark current with the electric field in the mid-bias range for all our diodes, which may be explained by the Poole-Frenkel effect.