Room temperature capacitance-voltage profile and photoluminescence for delta doped InGaAs single quantum well

Room temperature capacitance-voltage (C-V) profile and photoluminescence (PL) studies of δ-doped single InGaAs quantum well samples are reported. The purpose was to obtain the confined carrier occupancy in the conduction band offset and observe any relevant phenomena. The results show that the peak intensity of the C-V profiles was almost linearly proportional to sheet carrier concentration and the full width at half maximum of the C-V profiles became narrower with increasing doping level in the barrier layer. This is interpreted as being due to improved confinement of electrons as a result of band bending induced by the δ-doping layer. This explanation was further supported by PL data that show the transition corresponding to the dominant peak changed with different δ-doping levels and that all of the transitions were redshifted. Finally, theoretical calculations of the band structure based on a four band kp method are presented to explain the observed results.