Tailoring the Dimension of Halide Perovskites Enables Quantum Wires with Enhanced Visible Light Absorption

Dimensional engineering of organic-inorganic halide perovskite has been showing a promising application in solar cells, photodetectors, and light-emitting diodes (LED). New insights into modeling of one-dimensional halide perovskite is reported from firstprinciples calculation methods. One-dimensional hybrid perovskites quantum wires (QWs) are built based on the surface cleavage of FAPbI(3). Geometric relaxation shows that the edge-sharing octahedral lead iodine chains are surrounded by the organic cations FA to form a regular assembly of core-shell quantum wires. Analysis of band structure shows a direct band gap character of FAPbI(3) quantum wires. The cohesive energy of FAI-terminated perovskite QWs (FAI-QWs) is -4.81 eV while the cohesive energy of PbI-terminated perovskite QWs (PbI-QWs) is -4.05 eV. FAI-QWs exhibit a distortion of [PbI6] octahedra and an adjacent 45 degrees rotation of CH(NH2)(2)(+) ions at the corner of QWs crystal lattice, while FAI-QWs exhibit a < 5 degrees counterclockwise rotation of Pb-I bonds. The strong hybridization among Pb, I, N, and C clarifies the formation mechanism of quantum wire reconstruction, charge redistribution, and electron-hole excitation. Analysis of optical properties shows that enhanced absorption in the visible light region is obtained for the hybrid perovskites quantum wires, implying the promising application in solar cells and light emitters.