Surface studies by modulation spectroscopy

摘要: Abstract Surface barrier and electronic surface states are important parameters for characterizing semiconductor surfaces. Qualitative information on the electric field can be deduced from electroreflectance studies. Energetic positions of have been determined by spectroscopic methods using effect modulation techniques. Besides effects conductivity absorption , which limited to low densities states, new was gained investigating spectral dependence photoconductivity . Also phonons were detected in “spectral oscillations” photoconductivity. The measurement photovoltage at photon energies where bulk is transparent promises a tool state research future. To demonstrate these techniques examples given Ge, Si, ZnO, CdS