OPTICAL AND QUANTUM ELECTRONICS, vol.54, no.2, 2022 (SCI-Expanded)
This study investigates the terahertz performance of a voltage tunable AlGaAs/GaAs asymmetric step-like coupled double quantum well infrared photodetector structure based on intersubband transitions. The left part of the barrier is n-type doped to eliminate the interaction of the impurities with an electron in the quantum well. The coupled double quantum wells in the structure enable the adjustment of the dipole moment and the oscillator strength for the intersubband transition resonance absorption, providing wavelength tunable and selectable performance. When the applied voltage is increased, the photoresponse spectra dominated by a transition from the ground subband level to the second subband level with an energy of 17 meV (similar to 4.1 THz) shifts to the transition from the ground subband level to the first subband level with an energy of 10.2 meV (similar to 2.5 THz).