Optical properties of p-type InGaAs/AlGaAs multiple quantum well structures

摘要

Be-doped InGaAs/AlGaAs multiple quantum well (MQW) structures with different concentrations in the well material are characterized by photoluminescence (PL) technique. Two significant luminescence peaks were observed from the device structures and they both showed a red shift and broading in line width as doping concentration increases. Strong intersubband absorption originated from intersubband transitions of heavy holes between the ground state E_hh1 and the excited state E_hh2 was also observed and the maximum absorption wavelength was found to shift from 8.35 μm to 8.00 μm as the Be concentration increased from 10~17 cm~-3 to 2 × 10~19 cm~-3. These observations are in very good agreement with the theoretical estimation after taking the doping-induced changes in barrier height into account. Temperature dependence of the luminescence from the doped MQW structures indicates that the PL intensity can be described by an exponential relationship and the energy variation of the two PL peaks with temperature follow well with the Varshni's equation.