Evaluation of new multiple quantum well avalanche photodiode structures: the mqw, the doped barrier and doped quantum well

A quantitative experimental investigation of AlGaAs/GaAs multiple-quantum-well avalanche photodiode (APD) structures, the superlattice APD; the doped barrier APD and the doped quantum well APD is reported. Diodes exhibiting self consistent C-V, I-V and breakdown voltage characteristics showed strong agreement between electron- and hole-ionization rates, as determined from gain and noise measurements, respectively. This study provides new data on the performance of doped barrier and quantum well APDs and establishes a comparison with the electron- and hole-ionization rates from Al_xGa_1−xAs/GaAs MQW-APDs. These devices exhibit gains of ~ 20 with excess-noise factors <5 at bias voltages <10V. The dependence of these properties on structure, doping concentration, bias and temperature is presented.