Calculation of band offsets in Cd1−xXxTe alloys, X = Zn, Mg, Hg and Mn and magnetic effects in CdMnTe

Due to the large variety of properties offered by the telluride binaries CdTe, ZnTe, MgTe, HgTe and MnTe as well as their mixed ternary alloys, an accurate knowledge of their electronic band parameters is crucial. These materials have been extensively studied but, some points bearing on several properties have never previously reported or are still not clear. In this paper, we report results on the conduction and valence band offsets of the pseudo-morphically strained Cd1−xXxTe layer on relaxed Cd1−yXyTe substrate, X = Zn, Hg, Mg and Mn. Based on the Van Der Walle model, calculations have been performed for the all range of material and substrate 0 ≤ x,y ≤ 1. These discontinuities have not yet calculated for X = Mg, Mn or Hg in the all range 0 ≤ x,y ≤ 1. For the CdMnTe diluted magnetic semiconductor which we focus more interest due to its considerable current interest for applications, calculations have been done without and with correction taking into account magnetic effect of magnesium ions Mn2+. It is found that the introduction of only a few percent of Mn into CdTe provides a unique opportunity to combine two important fields in physics, semiconductivity and magnetism. We can take advantage both of possibility of applications in solid-state lasers and exceptional magnetic properties offered by this magnetic diluted semiconductor.This study presents important quantities that are required to model quantum structures and offers a fast and inexpensive way to check device designs and processes.

► The conduction and valence band offsets of the pseudo-morphically strained Cd1−xXxTe layer on relaxed Cd1−yXyTe substrate, are investigated for X = Zn, Mg, Hg and Mn in the entire range 0 ≤ x,y ≤ 1.
► For Cd1−xMnxTe diluted magnetic semiconductors, the exchange interactions are determined in the order to take into account magnetic effect.
► The conduction and valence band offsets of Cd1−xMnxTe/CdTe interface are calculated in the whole range of Mn composition x and for magnetic field values equal to 0 and 5 T.