Fabrication and characterization of uni-traveling-carrier photodetectors (UTC-PDs) with dipole-doped structure at InGaAs/InP interface

This paper describes the fabrication and high speed characterization for uni-traveling-carrier photodetectors (UTC-PD) with dipole-doping layers. The dipole-doping InGaAs/InP layer has been introduced at the InGaAs (absorption layer) and InP (collection layer) interface to prevent current blocking in our UTC-PD devices. These UTC-PDs have achieved high photocurrent of 52 mA, high responsivity of 0.44 A/W as well as high 3dB bandwidth of ~17.5 GHz. Furthermore, a UTC-PD equivalent circuit model is used to simulate and interpret device results of our UTC-PDs.