Influence of residual impurity background on the nonradiative recombination processes in high purity InAs/GaSb superlattice photodiodes

The influence of the impurity background on the recombination processes in type-II InAs/GaSb superlattice photodiodes with a cutoff wavelength of approximately 4.8 mu m was investigated by electroluminescence measurements. Using an iterative fitting procedure based on the dependence of the quantum efficiency of the electroluminescence on the injection current, the Auger and Shockley-Read-Hall lifetimes were determined for photodiodes with background concentration below 10(15) cm(-3). The authors determined in which range of the injection current Shockley-Read-Hall or Auger recombination is predominant. At T=300 K, the findings indicate that in high quality material with a low background concentration Auger effect becomes the prevalent mechanism even at low applied current. (c) 2006 American Institute of Physics.