Determination of polarity in noncentrosymmetric layer/substrate systems

Energy-dispersive anomalous X-ray scattering has been used for the determination of the polarity of a noncentrosymmetric layer/substrate system. The method was applied to an epitaxically grown (Ga,In)P layer on a (001) GaAs substrate as an example to show its applicability as a routine procedure for noncentrosymmetric thin-film systems. In the simplest case, four energy spectra of various orders of the 111 reflections were sufficient to identify polarity, without the need for intensity corrections.