InAs p-n diodes grown on GaAs and GaAs-coated Si by molecular beam epitaxy

Abstract

InAs p-n diodes have been grown on GaAs and GaAs-coated Si substrates by molecular beam epitaxy. Transmission electron microscopy cross sections of the epilayers demonstrate a good structural quality. Photodiodes were obtained using a Be (p=5×1016 cm−3) and Si (n=3×1016 cm−3) doping scheme. The diodes exhibited 77 K zero-bias resistance area products of 2200 cm2 for InAs/GaAs and 1500 cm2 for InAs/GaAs/Si. The spectral response of the devices peaked at 2.95 µm with Johnson noise limited detectivities D* of 7.0×1011 cm Hz1/2/W for InAs/GaAs and 5.8×1011 cm Hz1/2/W for InAs/GaAs/Si. These results clearly demonstrate the feasibility of the monolithic integration of InAs infrared detectors and GaAs or Si read-out electronics.