Results of experimental measurements and theoretical analysis are presented for the TiAu/ZnS/CdTe/HgCdTe metal–insulator–semiconductor heterostructure. The passivation of HgCdTe is provided by a double layer consisting of a dielectric ZnS placed on top of an epitaxial CdTe layer. Both HgCdTe and CdTe were grown by metalorganic chemical vapor deposition. Two types of CdTe layers were investigated: one was grown directly, in situ, immediately following the growth of HgCdTe; the second was grown indirectly using previously grown HgCdTe samples. It is shown that directly grown CdTe layers lead to low fixed interface charge, which is a good condition for passivation. The indirectly grown samples are still acceptable, but not as good as the directly grown samples. We demonstrate, on the basis of theoretical considerations, that the dielectric ZnS improves the flatband condition at the CdTe/HgCdTe interface.
The particle effective mass is often a challenging concept in solid state physics due to the many different definitions of the effective mass that are routinely used. Also, the most commonly used theoretical definition of the effective mass was derived from the assumption of a parabolic energymomentum realtionship, E(p), and therefore should not be applied to non-parabolic materials. In this paper, we use wave-particle duality to derive a definition of the effective mass and the energy-mass approximation suitable for non-parabolic materials. The new energy-mass relationship can be considered a generalization of Einstein's E = mc 2 suitable for arbitrary E(p) and therefore applicable to solid state materials and devices. We show that the resulting definition of the effective mass seems suitable for non-paraboic solid state materials such as HgCdTe, GaAs, and graphene.
The particle effective mass in graphene is a challenging concept because the commonly used theoretical expression is mathematically divergent. In this paper, we use basic principles to present a simple theoretical expression for the effective mass that is suitable for both parabolic and non-parabolic isotropic materials. We demonstrate that this definition is consistent with the definition of the cyclotron effective mass, which is one of the common methods for effective mass measurement in solid state materials. We apply the proposed theoretical definition to graphene and demonstrate linear dependence of the effective mass on momentum, as confirmed by experimental cyclotron resonance measurements. Therefore, the proposed definition of the effective mass can be used for non-parabolic materials such as graphene.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.