We report the room temperature characteristics of photoluminescence emission in delta-doped pseudomorphic high electron mobility transistor AlGaAs/InGaAs/GaAs structures. A theoretical self-consistent calculation of band structure demonstrates that dominant emissions are due to the transition from the second electron subband to the first heavy hole subband, namely, (e(2)-hh(1)). The calculation also predicts that along with the increase of the delta-doping level, the transition energies shift to lower energies. It is explained as band gap renormalization caused by change of confined levels by band bending and electrostatic attraction. The numerical fits to calculated transition energies show that (e(2)-hh(1)) obeys an exponential decay change and (e(1)-hh(1)) decreases linearly along with the increase of delta-doping level.