The II–VI group/monoamine hybrid was a novel inorganic/organic (I/O) layered structure and it exhibited a strong quantum confinement effect and well-defined Mn2+-doped luminescence, which was imperative and valuable academically for its application. In this work, the pure and well-crystalline (ZnS:Mn)2·oa (oa = octylamine) hybrid was prepared by solvothermal synthesis and its thin films were fabricated by the drop-casting method. The 5 at% Mn2+-doped hybrid exhibited a strong Mn2+ luminescence at 597 nm with a 300 nm excitation. The inner filter effect (IFE) for this luminescence was investigated and verified by detecting three selected environmental contaminant species: n-butyl xanthate (BX), crystal violet (CV), and reaction black 5 (RB5), which indicated that this hybrid thin film had a good luminescence IFE-based linear response for the μM species solution. Furthermore, the 597 nm luminescence remained intact for the solution with a pH from 4 to 10 and the hydrophobicity of the hybrid thin film was favorable for its rapid and multiple IFE-based detection. Therefore, this hybrid thin film is a competitive candidate for the new-generational fluorescence sensors to probe the occurrence of these environmental contaminants.

The (Zn0.95Mn0.05S)2·L (L = hexylamine and octylamine) hybrids show the optimal Mn2+ luminescence and their thin films were fabricated on the quartz substrate layer by layer by a spin coating method, which revealed the linear relationship of the UV optical absorption and the Mn2+ luminescence intensity with the layer numbers.

MnF2 nanocrystals were prepared by a solvothermal method. Its powder X-ray diffraction (XRD) pattern was indexed to the rutile-type structure with lattice constant a=4.857 and c=3.309 Å. The as-prepared MnF2 nanocrystals were spherical particles with a size of 40–60 nm by scanning electron microscopy analysis. Its optical absorption spectrum exhibited absorption features of Mn2+d−d transitions. The magnetic characterization indicated that the nanocrystals have antiferromagnetic–paramagnetic phase transition at 70.1 K and linear magnetization behavior at 2 K. The electronic structure of tetragonal MnF2 was studied by spin-polarized first-principle density-functional calculation with general gradient approximation (GGA) and pseudopotential localized basis sets, which shows that rutile-type MnF2 should be a three-dimensional paramagnetic insulator. Density of states (DOS) analyses indicate that the manganese 3d orbitals with α and β spin characters dominate the highest valence and lowest conduction bands, respectively. According to the calculated band structure, the optical absorption properties are attributed to d−d transition of the manganese ions. The agreement between simulated and observed absorption spectrum was obtained, which confirms that the present calculated results provide a reasonable description of the electronic structure of rutile-type MnF2.

CdSe·hda0.5 (hda = 1, 6-hexanediamine) is a kind of layered ordered-bonding inorganic/organic hybrid compound. Density functional calculation of CdSe·hda0.5 based on general gradient approximation was carried out to optimize its structure, analyze its energy band, and predict its optical and electric properties. The result shows that in CdSe·hda0.5, the distorted [CdSe3N] tetrahedra interlink with adjacent ones by sharing three Se vertices and form [CdSe] monolayers, which were separated by all-trans hda molecules with the space of 1.38 nm. Compared with bulk CdSe, CdSe·hda0.5 has a direct blue-shifted band gap at Brillouin zone center, narrowed highest valence band (HVB), and lowest conducting band (LCB) with doublet line character. The band-edge states show dispersion anisotropy between the in-plane and normal direction of [CdSe] monolayers, which was attributed to the layered structure character. The hda molecules function as an energy barrier to confine the valence electron in [CdSe] monolayer and result in strong quantum confinement effect in c direction, CdSe·hda0.5 can be consequently regarded as a two-dimensional (2D) semiconductor. The Cd- and Se-atom contributions dominate the band-edge density of states and determine the major optical and electrical properties of CdSe·hda0.5. Its electron mobility was estimated to be 16 cm2 V−1 s−1, which is comparable with other hybrid chalcogenides. The optical properties study reveals that, CdSe·hda0.5 possesses absorption anisotropy and sharp band-edge excitonic emission peak. The analysis of temperature dependence of photoemission spectra (7.5−295 K) indicate that, compared with CdSe bulk films, the 2D exciton of CdSe·hda0.5 has a blue-shifted fundamental state level with a 2-fold linear temperature coefficient, higher Debye temperature/average phonon energy, pronounced electron−phonon interaction and a higher excitonic binding energy (21.5 meV).

The (Zn0.95Mn0.05S)2·L (L = hexylamine and octylamine) hybrids show the optimal Mn2+ luminescence and their thin films were fabricated on the quartz substrate layer by layer by a spin coating method, which revealed the linear relationship of the UV optical absorption and the Mn2+ luminescence intensity with the layer numbers.