ELECTROREFLECTANCE

Publisher Website
Google Scholar
Abstract
Electroreflectance is the oldest of a growing number of differential reflectance techniques which form the derivative of the joint-density-of-states function by the periodic change of an external parameter such as the electric field. Since this function possesses analytic singularities at critical points, it is possible to lift these key parameters of band structure analysis from the large background absorption caused by non-critical areas of the Brillouin zone. Phase-sensitive synchronous observation of the field-induced reflectance change produces structure which is considerably enhanced compared with static reflectance measurements. This gain in resolution is not the essential feature of the new techniques, however. Some features of electroreflectance are discussed from which information can be derived on the symmetry character of a critical point and its location in the Brillouin zone. Elaborating on the case of silicon, it is pointed out that the interpretation of electroreflectance structure could lead to an expansion of certain aspects of band structure analysis derived from the results of previous static techniques. It is suggested that in the case of interband energy surfaces nearly flat in k-space, as for the 3.4 eV region of silicon, separate interpretation of static reflectance and electroreflectance is required, since the static spectrum may involve extended regions of the Brillouin zone while the derivative spectrum may relate to the critical points. The sensitivity of such a flat interband surface to distortion by changes in external parameters can cause changes in symmetry class and location of critical points

This publication has 0 references indexed in Scilit: