Electrical tunability of infrared detectors using compositionally asymmetric GaAs/AlGaAs multiquantum wells

For the first time, an electrically tunable infrared photoconductor is made with GaAs/AlGaAs asymmetric step multiquantum wells, using the linear Stark shift of the intersubband transition. An applied electric field excursion of ±40 kV/cm is sufficient to shift the peak responsivity wavelength from 8.5 to 13.5 μm. The photoresponse tunability is studied by comparing photocurrent and absorption spectra for different applied electric fields.