Novel modulation reflectance spectroscopy of semiconductor heterostructures

摘要

New methods of modulation reflectance spectroscopy have been proposed for investigation of semiconductor heterostructures. Current-, radio-frequency- and microwave-modulated reflectance are proposed and applied for determination of band structure features and band diagram of heterostructures of high electron mobility transistors and laser diodes. New physical contributions to formation of spectra of the modulation reflectance of light with quantum energy near the fundamental absorption edge are discussed. The main contributing mechanism, free carriers' heating, is associated with alternating current, radio-frequency and microwave electric field, or with radiation with photon energy below bandgap energy of semiconductor layers. Novel techniques of local excitation of the heterostructures by radio-frequency field or by pump light with scanning by probe signal are also proposed.