Electronic structures and magnetic properties of transition metal doped CsPbI$_{3}$ perovskite compounds by first-principles calculation

Transition metal doped cesium lead halide (CsPbI$_{3}$) perovskite compounds were studied for application in photovoltaic solar cells. Electronic structures, chemical shifts of $^{207}$Pb and $^{127}$I-NMR, vibration modesin infrared and Raman spectra of transition metals (Mn$^{2+}$, Fe$^{2+}$ or Cu$^{2+}$)-doped CsPbI$_{3}$ perovskite compounds were studied by the first-principles calculation using density functional theory. The CsPb(Fe)I$_{3}$ perovskite crystals had a slight perturbation of crystal field in the coordination structure.The electron density distribution was delocalized on the 5$p$ orbital of I atom, the 3$d$ orbital of Fe atom and the 6$p$ orbital of Pb atom. The first excited process was based on ligand metal charge transfer from the 5$p$ orbital on I atom to the 3$d$ orbital of Fe atom. The chemical shifts of $^{127}$I-NM Rwere associated with the electron correlation of electron-nuclear spin interaction and nuclear quadrupole interactions based on electron field graduate. The asymmetric vibrations of Pb-I bonds stretching mode related to electron conductivity with scattering of the carrier diffusion as phonon effectiveness. The slight perturbation of the coordination structure in the CsPb(Fe)I$_{3}$ perovskite crystal will improve the photovoltaic and optical properties.