PHOTOLUMINESCENCE ANALYSIS OF INALAS-INGAAS HFET MATERIAL WITH VARIEDPLACEMENT OF HEAVY DELTA-DOPING

Low temperature photoluminescence (PL) has been used to characterize I nAlAs/InGaAs/InP heterojunction field-effect transistor (HFET) structu re material. A phenomenological lineshape model has been applied to th e PL spectrum to derive energy levels and the position of the Fermi-en ergy and hence the channel carrier concentration. The data is compared with results from low-temperature Hall and Shubnikov-de Hans (SdH) me asurements, and fit with a charge-control model of the conduction band . Values for the sheet density are derived from PL for channel-doped s tructures where SdH measurements are difficult. Changes in the quantum well symmetry through variations in the dopant distribution are shown to be reflected in the PL lineshape.