Only a selected group of two-dimensional (2D) lead halide perovskites shows a peculiar broad-band photoluminescence. Here we show that the structural distortions of the perovskite lattice can determine the defectivity of the material by modulating the defect formation energies. By selecting and comparing two archetype systems, namely, (NBT)(2)PbI4 and (EDBE)PbI4 perovskites (NBT = n-butylammonium and EDBE = 2,2-(ethylenedioxy)bis(ethylammonium)), we find that only the latter, subject to larger deformation of the Pb-X bond length and X-Pb-X bond angles, sees the formation of V-F color centers whose radiative decay ultimately leads to broadened PL. These findings highlight the importance of structural engineering to control the optoelectronic properties of this class of soft materials.
Broadband emission in two-dimensional hybrid perovskites: The role of structural deformation
Mosconi, Edoardo;De Angelis, Filippo
;
2017
Abstract
Only a selected group of two-dimensional (2D) lead halide perovskites shows a peculiar broad-band photoluminescence. Here we show that the structural distortions of the perovskite lattice can determine the defectivity of the material by modulating the defect formation energies. By selecting and comparing two archetype systems, namely, (NBT)(2)PbI4 and (EDBE)PbI4 perovskites (NBT = n-butylammonium and EDBE = 2,2-(ethylenedioxy)bis(ethylammonium)), we find that only the latter, subject to larger deformation of the Pb-X bond length and X-Pb-X bond angles, sees the formation of V-F color centers whose radiative decay ultimately leads to broadened PL. These findings highlight the importance of structural engineering to control the optoelectronic properties of this class of soft materials.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
