High-speed GaAs/AlGaAs photoconductive detector using a p-modulation-doped multiquantum well structure

A new type of high-speed GaAs/AlGaAs photoconductive detector utilizing the high drift velocity of minority electrons in a p-modulation doped multiquantum well structure is demonstrated. In this modulation-doped structure, the electron scattering is reduced, which leads to the enhancement of the electron (minority carrier) drift velocity which determines the response speed of the detector. A deconvolved pulse response as narrow as 33 ps full width at half-maximum was obtained with an electric field of 3.1 kV/cm at room temperature.