Optical investigations on pseudomorphic δ-doped AlGaAs/InGaAs/GaAs quantum wells

In this paper, photoluminescence (PL) measurements were performed on several series of single-side Si doped MBE pseudomorphic high electron mobility transistors (p-HEMTs) quantum well samples, with different spacer layer widths, well widths and Si (delta)-doped concentrations, under different temperatures and excitation power densities. PL signals from the transitions of the second electron subband to the first heavy-hole subband (e2-hh1) and the first electron subband to the first heavy-hole subband (e1-hh1) have been observed with good symmetry and narrow full with at half maximum indicating high sample quality compared with previous reported results. The dynamic competitive luminescence mechanism between the radiations of e2-hh1 and e1-hh1 was discussed in detail. The confining potential, subband energies, corresponding envelope functions, subband occupations and transferring efficiency have been calculated by self-consistent definite differential method at different temperatures in comparison with our experiment results. The relative variation of the integrated luminescence intensity of the two transitions (e1-hh1 and e2-hh1) was found to be dependent on the temperature and the structure's properties, e.g. spacer layer width, dopant concentration and well width, which is an efficient characterization method before p-HEMTs device fabrication.