Photovoltaic effect in methylammonium lead triiodide single crystal.

Due to the crystalline acentricity leading to the bulk photovoltaic effect (PV) the ferroelectrics (FEs) are considered as important candidates for creation of the PV cells overcoming the Shockley-Queisser limit of semiconductors. However, this research direction still requires more investigations to develop reliable pathways for PV efficiency optimization. The recent progress in the power conversion efficiency of the cells based on the organic-based compounds such as CH₃NH₃PbI₃perovskite attracted much attention of the scientists. Unfortunately, manufacturing of these multilayer cells implies a very complicated technology and very high price of the devices. Under such circumstances investigations of the PV effect in the single crystals of FE perovskites look very promising. In this paper we report that due to the sample illumination with intensive UV light, CH₃NH₃PbI₃single crystal is transformed from the pristine antiFE into the FE state. As a result, the PV effect characteristic of the FEs is realized in this material. The theoretically maximal value of the power conversion efficiency in this case was found to be one of the largest among the single crystals of this class of ferroics. We also considered the ways allowing to increase the PV efficiency of the potential solar cells based on such materials.