Films and crystalline powder of BiI3 intercalated with ammonia

Intercalation, i.e. the insertion of guest species in a crystalline layered structure, is an efficient route for generating new materials with novel properties. Thin films and crystalline powder of BiI3 layered semiconductor were intercalated by exposure to ammonia vapors at room temperature. The intercalated compound was studied by thermo-gravimetric analysis, differential scanning calorimetry, X-ray diffraction, UV–vis optical absorption, FTIR spectroscopy and Raman scattering. After exposure of BiI3 to ammonia the formation of a new phase, BiI3(NH3)3.83, was evidenced by thermal analysis. The intercalation process leads to a blue shift of the BiI3 optical absorption edge by 0.5 eV. The appearance of new Raman lines at 135 and 353 cm−1 in the Raman spectrum of intercalated BiI3 is considered as an evidence of the chemical interaction between the ammonia molecules and BiI3 lattice.