Investigation of deep level defects on Beryllium compensation doping of InGaAs/GaAsSb type-II superlattice photodiodes.

In this paper, deep level transient spectroscopy (DLTS) characterization was performed on Beryllium compensation doping of InGaAs/GaAsSb type-II superlattice photodiode. Three electron traps with the energy levels located at E-0.11 eV (E1), E-0.28 eV (E2), E-0.17 eV (E3), and a hole trap situated at E + 0.25 eV (H1) were revealed. The position distribution and depth concentration of these traps in SL absorption region was also explored. Furthermore, the bandlike states (E2) and localized states (E1 and H1) of extended defects were confirmed by DLTS measurements as a function of the filling-pulse time, these traps as generation-recombination centers are responsible for dominant dark current.