Structural and chemical stability of halide perovskites

Ab initio, crystal field and experimental spectroscopic studies of pure and Ni2+-doped KZnF3 crystals

“…The difference between these values and experimental data (4.0611 Å [26]) is þ2.19% and À1.97%, respectively. The other calculated values reported earlier (all in Å) 3.973 (LDA), 4.129 (GGA) [25] and 3.897 [31] are all close to our results, which confirms validity and reliability of the performed calculations. As a common feature with the previous results, our calculations show the LDA/GGA lattice constants to be a little under-/overestimated, respectively, with respect to the experimental data.…”

The crystal structure and upconversion properties of Yb3+, Er3+/Ho3+ codoped BaLiF3 microcrystals with different morphologies

“…Among these complex metal fluorides, barium lithium fluoride (BaLiF 3 ) plays a dominant role due to its specific electrical properties, good homogeneous optics, low phonon energy, and high thermal stability. [16][17][18] However, as a host of ideal optical materials, the UCL properties of the crystal BaLiF 3 have not been systematically investigated. [16][17][18] However, as a host of ideal optical materials, the UCL properties of the crystal BaLiF 3 have not been systematically investigated.…”

“…11 The BaLiF 3 crystal has an inverted perovskite structure with a wide energy band gap in the cubic phase whose space group is O 1 h or Pm3m, and it can be easily doped with various RE ions. [16][17][18] However, as a host of ideal optical materials, the UCL properties of the crystal BaLiF 3 have not been systematically investigated. Generally, pure and doped BaLiF 3 crystals are prepared via the solid-state reaction from stoichiometric mixtures of highly purified LiF and BaF 2 with other relevant RE fluoride dopants.…”

Recrystallization and phase stability study of cesium tin iodide for application as a hole transporter in dye sensitized solar cells

“…This SnI 2 undergoes photochemical reactions enhanced by visible and UV radiation initially to black SnO and further to white and insoluble SnO 2 powder. CsSnI 3 perovskite stability depends on the Sn cation [13], and the hypervalent Sn(II) cation undergoes spontaneous oxidation with small activation energy under ambient conditions making B-CsSnI 3 unstable under ambient conditions [13,14].…”