Characterisation, modelling and design of cut-off wavelength of InGaAs/GaAsSb type-II superlattice photodiodes

Abstract InGaAs/GaAsSb type-II superlattice (T2SL) photodiodes grown on InP substrates are an alternative detector technology for applications operating in the short wavelength infrared band. Their cut-off wavelengths heavily influenced by thickness and material composition of InGaAs GaAsSb used T2SL. We present a single band k.p. model performed using finite difference approach nextnano validated against two T2SL photodiode wafers results from literature. These cover both lattice matched strained GaAs 1− x Sb compositions ( = 0.40, wafer A 0.49, B). The validation data covers temperature dependence (obtained phase-sensitive photo response data) 200 K to room temperature. were found reduce at 1.32 nm −1 1.07 B. Good agreement was achieved between simulations, after altering valance offset (VBO) bowing parameter −1.06 eV. Using this model, we show that wavefunction overlap drops significantly if barrier is thicker than well layer, hence defining upper limit layer. This then demonstrate there linear maximum achievable also adoption 5 nm/3 structure offers improved over more common nm/5 designs. reported paper available doi: 10.15131/shef.data.20310591.