Based on the principle of density matrix and the finite element method, the interband optical absorption between the electron and hole has been investigated in a wurtzite [Formula: see text] spherical core–shell quantum dot (CSQD) including a strong built-in electric field (BEF). We have studied the effects of the size and the ternary mixed crystal on the optical absorption coefficients (ACs) and refraction index changes (RICs). The results indicate that the absorption peaks of ACs and RICs decrease rapidly, and show a redshift with the increase of the component [Formula: see text]. It is also found that the absorption peaks of ACs and RICs reduce obviously and depend on the core radius and the well width. When the core radius increases, the positions of the maximum ACs and RICs show a blueshift. At the same time, it presents a redshift when the well width increases. Particularly, the influence of the well width is much stronger than the core radius in the wurtzite [Formula: see text] spherical CSQDs. We hope that these results could provide guidance on both theoretical and experimental study related to the optical properties of spherical CSQDs.

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CdMnTe is demonstrated to be a good candidate in the X-ray and [Formula: see text]-ray detector application, however, there are few reports on theoretical analysis of electron scattering rate in CdMnTe quantum well. Within the framework of effective mass approximation and envelope function approximation, the influence of the Mn alloy composition ([Formula: see text], the well width ([Formula: see text], the electron temperature ([Formula: see text] and the electron density ([Formula: see text] on the electron–electron scattering rate (1/[Formula: see text] in the CdTe/Cd[Formula: see text]Mn[Formula: see text]Te single quantum well (SQW), are simulated by shooting method and Fermi’s Golden Rule. The results show that 1/[Formula: see text] is significant inverse proportional to [Formula: see text], but positively proportional to [Formula: see text] and [Formula: see text]. Except for a small peak at 20 K, 1/[Formula: see text] is not sensitive to [Formula: see text]. The above differential dependency of 1/[Formula: see text] on [Formula: see text] and [Formula: see text] can be interpreted by sub-band separation ([Formula: see text], which is proportional to [Formula: see text] but inversely proportional to [Formula: see text]. When [Formula: see text] decreases gradually, the electron transition becomes easier, which leads to 1/[Formula: see text] increases. The dependency of 1/[Formula: see text] on [Formula: see text] can be interpreted by kinetic energy of electrons. The larger the electron kinetic energy is, the more difficult the electron transition from first excited state to ground state is, which leads to 1/[Formula: see text] decreasing. The dependency of 1/[Formula: see text] on [Formula: see text] can be interpreted by the Coulomb interaction between electrons, i.e., the increase of electron collision probability caused by the increase of [Formula: see text].