Design of 1D/2D/3D perovskite composites for enhancing the stability of high efficiency solar cells

This project will investigate the nature of 1D,2D/3D perovskite interactions in order to design highly stable composites for next generation of efficient solar cells. The goal is to learn the design principles for ultrastable perovskite composite films. It will do so by engineering the spacer cation chemistry and the materials processing, gaining control of these interactions to achieve over two orders of magnitude stability improvement. We will focus on achieving highly stable solar cells with state-of-the-art efficiencies by designing next generation perovskite films comprising of composite mixtures of low-dimensional (1D and 2D) and three dimensional (3D) materials. We will approach this challenge by controlling the spacer cation chemistry to create water-stable and low dimensional perovskite materials. We will prepare composite films with 1D/3D and 2D/3D perovskite combinations and study how film deposition processing affects charge transport, devices performance and temporal stability. The project aims to gain a deeper understanding of the interactions between the different perovskite components. We seek to identify the critical insights and define better guidelines for the design of next generation very stable, highly efficient perovskite solar cells. We will use in-situ and ex-situ grazing incidence wide-angle X-ray scattering (GIWAXS) to assess the rates of spin-coated film formation and to observe intermediates which lead to the final film. We will study the influence of the spacer cation chemistry on the mechanism of texture and layer orientation within the 2D/3D composite films using GIWAXS done at synchrotron facilities. This project will provide key information on how interfacial engineering, ligand chemistry and compositional engineering in the 2D QW layer influence the desirable electronic properties of the 2D/3D hierarchical films and solar cell performance. The goal is to learn the design principles for ultrastable perovskite film composites and advance the stability of efficient solar cells to bring them closer to practical applications and widespread employment benefiting the Navy.