Local and Long Range Structural Studies of Hybrid Perovskites

In this work we study a class of hybrid$_{\mathrm{\thinspace }}$perovskites with high photovoltaic conversion efficiency which exhibits an anomalous transition near \textasciitilde 330 K (T*). Local structural measurements over a broad temperature range have been conducted and compared with single crystal diffraction measurements. The detailed motion of atoms is extracted and the response to chemical modification is explored. Extensive modeling of the temperature dependent structure is conducted. The connection of the structure to the novel transport properties will be discussed. This work is supported by DOE Grant DE-FG02$-$07ER46402.