Nonequilibrium radiation of long-wavelength InAs∕GaSb superlattice photodiodes

Abstract

The emission behavior of binary-binary type-II $\mathrm{In}\mathrm{As}∕\mathrm{Ga}\mathrm{Sb}$ superlattice photodiodes has been studied in the spectral range between 8 and $13\mu \mathrm{m}$ . With a radiometric calibration of the experimental setup the internal and external quantum efficiencies have been determined in the temperature range between 80 and $300\mathrm{K}$ for both the negative and positive luminescences. The negative luminescence efficiency approaches values as high as 35% without antireflection coating. An analytic description of the temperature dependence of the internal quantum efficiency around a zero-bias voltage allows for the determination of the coefficient for electron-hole-electron Auger recombination ${\Gamma }_n=1\times {10}^{24}{\mathrm{cm}}^6{\mathrm{s}}^{-1}$ . For an $n$ -type material, the minority-carrier lifetime is provided as a function of band gap and temperature, explaining the strong decrease of the minority-carrier lifetime in the case of an $n$ -type residual background exceeding $1\times {10}^{16}{\mathrm{cm}}^{-3}$ . Furthermore, an analytic expression of the quantum efficiency for the radiation upon forward-bias conditions is given.