On the band diagram of Mg_2Si/Si heterojunction as deduced from optical constants dispersions

摘要

The optical constant dispersions of ion-beam-synthesized Mg_2Si phase in Si matrix are obtained from the transmittance and reflectance spectra. Two types of samples are studied - one of them with Mg_2Si phase embedded in n-type (100)Si and the other with Mg_2Si phase embedded in ρ-type (100)Si. The formation of the phase is proved by Raman scattering and infrared transmittance measurements. From the interpretation of the optical constant dispersions, the energies of the transitions nearby the material band edge are determined. As a result the band diagram of the heterojunction Mg_2Si/Si is obtained. The results about the Mg_2Si band gap value are compared with the theoretically predicted and experimentally determined ones. The value of the conduction band offsets of Mg-2Si and Si is not reported by now.