title: Tuning the band gap in hybrid tin iodide perovskite semiconductors using structural templating.
abstract: Structural distortions within the extensive family of organic/inorganic hybrid tin iodide perovskite semiconductors are correlated with their experimental exciton energies and calculated band gaps. The extent of the in- and out-of-plane angular distortion of the SnI4(2-) perovskite sheets is largely determined by the relative charge density and steric requirements of the organic cations. Variation of the in-plane Sn-I-Sn bond angle was demonstrated to have the greatest impact on the tuning of the band gap, and the equatorial Sn-I bond distances have a significant secondary influence. Extended Hückel tight-binding band calculations are employed to decipher the crystal orbital origins of the structural effects that fine-tune the band structure. The calculations suggest that it may be possible to tune the band gap by as much as 1 eV using the templating influence of the organic cation.
authors.affiliation: Department of Chemistry, North Carolina State University, Box 8204, Raleigh, North Carolina 27695, USA.
authors.forename: Jeremy L
authors.initials: JL
authors.lastname: Knutson
authors.forename: James D
authors.initials: JD
authors.lastname: Martin
authors.forename: David B
authors.initials: DB
authors.lastname: Mitzi