MODULATION SPECTROSCOPY OF SEMICONDUCTOR MICROSTRUCTURES

This paper reviews some recent interesting applications of modulation spectroscopy to study the electronic transitions in GaAs GaAlAs parabolic quantum wells, short-period, strained layer |frsol|GeSi/Si, GeSi Ge and GeSi Ge0.8Si0.2 superlattices and strained layer InGaAs GaAs single quantum wells. In addition, the discussion will include the use of SIN+ (SIP+) structures to evaluate surface electric fields and hence Fermi level pinning, investigation of epilayers/heterojunctions, studies of the two-dimensional electron gas in modulation-and δ-doped material, work on actual device structures such as HBTs and finally a new variation of the modulation method of differential reflectance. © 1991.