RESUMO
Two-dimensional organic-inorganic hybrid Ruddlesden-Popper perovskites have attracted a lot of attention due to their unique photochemical properties and enhanced stability towards photoluminescence devices. Compared with three-dimensional materials, two-dimensional perovskites show great potential for photoelectric applications due to their tunable band gap, great excitation binding energy, and large crystal anisotropy. Although the synthesis and optical properties of BA2PbI4 crystals have been extensively studied, the role of their microstructure in photoelectric applications, their electronic structure, and their electron-phonon interaction are still poorly understood. In this paper, based on the preparation of BA2PbI4 crystals, the electronic structure, phonon dispersion, and vibrational properties of BA2PbI4 crystals were revealed in detail with the help of density functional theory. The BA2PbI4 stability diagram of formation enthalpy was calculated. The crystal structure of the BA2PbI4 crystals was characterized and calculated with the aid of Rietveld refinement. A contactless fixed-point lighting device was designed based on the principle of an electromagnetic induction coil, and the points with different thicknesses of BA2PbI4 crystal were tested. It is proved that the excitation peak of the bulk is 564 nm, and the surface luminescence peak is 520 nm. Phonon dispersion curves and the total and partial phonon densities of states have been calculated for the BA2PbI4 crystals. The calculated results are in good agreement with the experimental Fourier infrared spectra. Besides the basic characterization of the BA2PbI4 crystals, the photoelectrochemical properties of the materials were also studied, which further proves the excellent photoelectric properties of the BA2PbI4 crystals and the broad application prospect.
RESUMO
CsPbX3 (X = Cl, Br or I) perovskite quantum dots (PQDs) have gained increasing interest due to their superior performance in photoelectric applications. In our work, a series of Mn2+ doped CsPbBr3 PQDs were successfully prepared in glasses by melt quenching and in situ crystallization technique. Due to the 4T1 (4G)â6A1 (6S) transition of Mn2+, a slight red shift from 510 nm to 516 nm was found, with the FWHM expansion from 18 nm to 26 nm. The PQDs@glasses showed excellent thermal stability, and the exciton binding energy reached a high level of 412 meV. The changes of the electronic structure after Mn doping CsPbBr3 can be demonstrated by first principles. Finally, a contactless electroluminescence device with the PQDs@glasses was designed based on the principle of electromagnetic induction, which is a potential application for detecting distance in sterile and dust-free environments.