29 January 2014Strong room-temperature ultraviolet to red excitons from inorganic organic-layered perovskites, (R-NH3)2MX4 (M=Pb2+, Sn2+, Hg2+; X=I−, Br−)
Many varieties of layered inorganic-organic (IO) perovskite of type (R-NH3 )2 MX4 (where R: organic moiety, M: divalent metal, and X: halogen) were successfully fabricated and characterized. X-ray diffraction data suggest that these inorganic and organic structures are alternatively stacked up along c -axis, where inorganic mono layers are of extended corner-shared MX6 octahedra and organic spacers are the bi-layers of organic entities. These layered perovskites show unusual room-temperature exciton absorption and photoluminescence due to the quantum and dielectric confinement-induced enhancement in the exciton binding energies. A wide spectral range of optical exciton tunability (350 to 600 nm) was observed experimentally from systematic compositional variation in (i) divalent metal ions (M=Pb2+ , Sn2+ , Hg2+), (ii) halides (X=I − and Br − ), and (iii) organic moieties (R). Specific photoluminescence features are due to the structure of the extended MX 2− 4 network and the eventual electronic band structure. The compositionally dependent photoluminescence of these IO hybrids could be useful in various photonic and optoelectronic devices.
Shahab Ahmad,
G. Vijaya Prakash,
"Strong room-temperature ultraviolet to red excitons from inorganic organic-layered perovskites, (R-NH3)2MX4 (M=Pb2+, Sn2+, Hg2+; X=I−, Br−)," Journal of Nanophotonics 8(1), 083892 (29 January 2014). https://doi.org/10.1117/1.JNP.8.083892
Shahab Ahmad, G. Vijaya Prakash, "Strong room-temperature ultraviolet to red excitons from inorganic organic-layered perovskites, (R-NH3)2MX4 (M=Pb2+, Sn2+, Hg2+; X=I−, Br−)," J. Nanophoton. 8(1) 083892 (29 January 2014)