HYBRID SHUBNIKOV-DEHAAS PHOTOLUMINESCENCE ANALYSIS OF 2-DIMENSIONAL ELECTRON-DENSITY IN STRAINED-QUANTUM-WELL STRUCTURES WITH HEAVILY-DOPEDCONTACT LAYERS

A hybrid analysis technique is presented to accurately extract the two -dimensional (2D) electron density of PHEMT structures in which multip le subbands are occupied and severe parallel conduction by heavily dop ed contact layers occurs. Complications due to shorted Hall voltages b y the parallel contact layer, which precludes simple Hall analysis, an d to multiple subband occupation, which requires high magnetic-field s weeps in Shubnikov-de Haas (SdH) measurements, are eliminated by this hybrid analysis that combines SdH measurements with photoluminescence measurements to extract the total 2D density. Comparisons with other m ethods demonstrate the high accuracy of this new technique.