Computational study of electronic, magnetic, and optical properties of Fe(II) mono-doped and (Fe(II), Al) co-doped ZnTe

•Al co-doping transforms Fe(II)-doped-ZnTe's ground state from AFM to FM.•The d-d transition peak of Fe(II) ion in absorption spectra is observed in infrared region.•The optical absorption peaks in the infrared region is attributed to the d-d transition in Fe(II) ions in the ZnTe lattice.•In AFM/FM coupled ion systems, the d-d transition peaks and fundamental bandgap energy both exhibit blue/red shift.