Inversion-channel resonant-cavity-enhanced field-effect photodetector for 2D OEIC applications

The operation of the inversion-channel Resonant-Cavity Enhanced (RCE) photodetector is demonstrated in a configuration compatible with the Vertical Cavity Surface Emitting Laser (VCSEL). The phototransistor used 3 strained InGaAs/GaAs quantum well's as the absorbing region and a post-growth dielectric top stack. A quantum efficiency of 41% was obtained at a resonant wavelength of 0.94 micrometers , thereby giving a resonant enhancement factor of 13.5. A bipolar transistor gain of 6.8 at a current density of 10 A/cm2 allowed the phototransistor responsivity to reach 2.1 A/W at the resonant wavelength. We also demonstrate the movement of the resonant peak through the use of Focussed Ion-Beam (FIB) etching which has potential applications in Wavelength Division Multiplexed (WDM) systems.