Band-bending effect of low temperature GaAs on a pseudomorphic modulation-doped field-effect transistor

Low temperature photoluminescence (PL) measurements on pseudomorphic modula tion-doped transistors with a low-temperature (LT) GaAs layer in the GaAs b uffer layer clearly show a decrease in the quantum well PL transition energ ies compared to a structure with no LT GaAs. Self-consistent calculations o f the electron and hole bandstructure suggest that the observed increase in the redshift in PL energies with increasing quantum well-LT GaAs spacing c an be attributed to band bending induced by the Fermi level pinning at the undoped GaAs/LT GaAs interface and a novel carrier compensation effect of L T GaAs.