Tuesday, 01 March, 2016

Control of Perovskite Crystal Growth by Methylammonium Lead Chloride Templating;

A. Binek, I. Grill, N. Huber, K. Peters, A. G. Hufnagel, M. Handloser, P. Docampo, A. Hartschuh and T. Bein -
Chemistry-an Asian Journal, 10.1002/asia.201501379 (2016)

State-of-the-art solar cells based on methylammonium lead iodide (MAPbI₃) now reach efficiencies over 20 %. This fast improvement was possible with intensive research in perovskite processing. In particular, chloride-based precursors are known to have a positive influence on the crystallization of the perovskite. Here, we used a combination of in-situ X-ray diffraction and charge-transport measurements to understand the influence of chloride during perovskite crystallization in planar heterojunction solar cells. We show that MAPbCl₃ crystallizes directly after the deposition of the starting solution and acts as a template for the formation of MAPbI₃. Additionally, we show that the charge-carrier mobility doubles by extending the time for the template formation. Our results give a deeper understanding of the influence of chloride in the synthesis of MAPbI₃ and illustrate the importance of carefully controlling crystallization for reproducible, high-efficiency solar cells.

Article on journal´s webpage