Ordered Perovskite Structure with Functional Units for High Performance and Stable Solar Cells.

Ion migration is one of the most critical challenges that affects the stability of metal-halide perovskite solar cells. However, the current arsenal of available strategies for solving this issue is limited. Here, we construct novel perovskite active layers following the concept of ordered structures with functional units (OSFU) to intrinsically suppress ion migration, in which a three-dimensional (3D) perovskite layer is deposited by vapor deposition for light absorbing and a 2D layer is deposited by solution process for ion inhibition. As a promising result, the activation energy of ion migration increased from 0.36 eV for the conventional perovskite to 0.54 eV for the OSFU perovskite. These devices exhibit substantially enhanced operational stability in comparison with the conventional ones, retaining >85% of their initial efficiencies after 1200 h under ISOS-L-1. Moreover, the OSFU devices show negligible fatigue behavior with a robust performance under light/dark cycling aging test (ISOS-LC-1 protocol), which demonstrate the promising application of functional motif theory in this field. This article is protected by copyright. All rights reserved.