In0.83Ga0.17As photodetectors with different doping concentrations in the absorption layers

The performances of wavelength-extended In0.83Ga0.17As PIN photodetectors with 8 × 1015 or 4 × 1016 cm−3 doped absorption layers were investigated and compared at different temperatures and bias voltages. Results displayed that they showed comparable device performance around room temperature and low bias voltages, but relatively large difference at lower temperatures and higher bias voltages. At lower operation temperatures the In0.83Ga0.17As photodetectors with 8 × 1015 cm−3 doped absorption layers showed smaller dark currents and higher resistance area products R0A than those with 4 × 1016 cm−3 doped absorption layers. It was ascribed to the reduced trap-assisted tunneling dark current in the photodetector with the lower doped In0.83Ga0.17As absorber layer.