Insight into the Origins of Figures of Merit and Design Strategies for Organic/Inorganic Lead-Halide Perovskite Solar Cells

Organic/inorganic lead-halide perovskite and its solar cells (SCs) present a new research platform for the study of special photophysical and photovoltaic (PV) characteristics across materials science, chemistry, physics, and engineering disciplines. However, the current understanding of the crystal structures, origins of figures of merit, and design strategies of SCs is inadequate. These key parameters are critical for exploring further applications of organometallic-halide perovskite films and their SCs. Therefore, herein, the material characteristics of lead-halide perovskite are introduced, the origins of open-circuit voltages, short-circuit current densities, and fill factors are explored, and three design strategies using interface engineering, bandgap engineering, and process-control engineering for high-quality perovskite active-layer fabrication, outstanding efficiency, and stable SCs are summarized. Herein, process-control engineering is introduced for the first time in perovskite SCs. Based on favorable synergistic effects, these structural features, origins of crucial parameters, and design strategies all promote the development of new schemes to explore the underlying physics, optimize functional layers and cell architectures, and improve final PV performance and device stability.