Dark current optimisation for MOVPE grown 2.5 μm wavelength InGaAs photodetectors

We have fabricated 2.5μmn InGaAs photodetectors, which exhibit state-of-the-art dark current densities (1O⁹A/cm² at 150K, -1OmV). The major parameter was the doping level of the absorbing layer. Measuring the dark current against temperature allows us to separate it into three different contributions, Also, the spectral response of the photodetectors was discussed as a function of the absorbing layer´s doping level