Science. 1995 Mar 10;267(5203):1473-6. doi: 10.1126/science.267.5203.1473.
Single crystals of the layered organic-inorganic perovskites, NH(2)C(I=NH(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.
采用水溶液生长技术制备了层状有机-无机钙钛矿NH(2)C(I=NH(2))(CH(3)NH(3))m SnmI3m+2 的单晶。与最近发现的（C(4)H(9)NH(3))(2)(CH(3)NH(3))n-1SnnI3n+1 家族不同，后者由（100）终止的钙钛矿层组成，结构测定揭示了一个具有一组 m <110> 取向的 CH(3)NH(3)SnI(3)钙钛矿片的不寻常结构类型，这些钙钛矿片由碘甲酰胺阳离子隔开。尽管 m = 2 化合物具有 0.33 +/- 0.05 电子伏特的带隙，是半导体，但随着 m 的增加，其具有更多的金属特性。通过选择有机阳离子来控制钙钛矿片取向的能力展示了有机-无机钙钛矿提供的灵活性，并为在层状钙钛矿中调整和理解低维输运提供了一个重要的手段。
