title: Conducting Layered Organic-inorganic Halides Containing <110>-Oriented Perovskite Sheets.
abstract: Single crystals of the layered organic-inorganic perovskites, [NH(2)C(I=NH(2)](2)(CH(3)NH(3))m SnmI3m+2, were prepared by an aqueous solution growth technique. In contrast to the recently discovered family, (C(4)H(9)NH(3))(2)(CH(3)NH(3))n-1SnnI3n+1, which consists of (100)-terminated perovskite layers, structure determination reveals an unusual structural class with sets of m <110>-oriented CH(3)NH(3)SnI(3) perovskite sheets separated by iodoformamidinium cations. Whereas the m = 2 compound is semiconducting with a band gap of 0.33 +/- 0.05 electron volt, increasing m leads to more metallic character. The ability to control perovskite sheet orientation through the choice of organic cation demonstrates the flexibility provided by organic-inorganic perovskites and adds an important handle for tailoring and understanding lower dimensional transport in layered perovskites.
authors.forename: D B
authors.initials: DB
authors.lastname: Mitzi
authors.forename: S
authors.initials: S
authors.lastname: Wang
authors.forename: C A
authors.initials: CA
authors.lastname: Feild
authors.forename: C A
authors.initials: CA
authors.lastname: Chess
authors.forename: A M
authors.initials: AM
authors.lastname: Guloy