The commercialization of perovskite photovoltaic technology is dependent on the development of high‐efficiency, stable, and large‐area solar modules. Despite the rapid rise in efficiencies of laboratory‐scale perovskite solar cells (PSCs), there is still a big gap in the transition from small‐area devices to large‐area perovskite solar modules (PSMs). Herein, recent progresses on scaling‐up PSMs are reviewed: first, multifarious scalable preparation methods, solvent engineering, and corresponding morphology control strategies for large‐area homogeneous perovskite films are summarized. Various charge carrier transport materials, electrode materials, and their scaling methods for high‐efficiency and stable PSMs are then outlined and the device structure design of PSMs is discussed. Finally, the current strategies for optimizing the environmental stability of devices are highlighted, and packaging for reducing lead leakage during operation is discussed.

Two-dimensional perovskites have widely been used to improve the efficiency and stability of perovskite solar cells and are generally believed to passivate defects at the grain boundaries of threedimensional perovskites. Herein, we studied introducing various combinations of two-dimensional phenyl ethylammonium lead iodide (PEA 2 PbI 4 ) and methylammonium chloride (MACl) to the formamidinium lead iodide (FAPbI 3 ) precursor solution. Ultralow dose selected area electron diffraction studies prove that the high density of intragrain planar defects in FAPbI 3 can be strongly reduced by adding PEA 2 PbI 4 and fully eliminated by adding further MACl. Although PEA + is too large to incorporate into FAPbI 3 , PEA 2 PbI 4 not only improves crystallization but also suppresses intragrain defect formation. As a result, a longer charge carrier lifetime, higher photoluminescence quantum yield, lower Urbach energy, and current−voltage hysteresis are achieved, resulting in a champion PCE of 23.69%, with an improvement of humidity stability.

increased over the past decade. This is attributed to the intrinsically excellent photoelectric properties of photoactive perovskite materials, including tunable bandgap, high absorption coefficient, long carrier diffusion length, high photoluminescence quantum yield, and high color purity. [3][4][5] However, the long-term instability of PSCs [6] and PeLEDs [7] limits future commercialization. Device performance gradually degrades under external stimuli, such as moisture, oxygen, light, heat, and electric fields, [8] causing photocarrier recombination and ion migration [9] which are intimately linked to the device microstructure. [10,11] Perovskites are typically fabricated through techniques such as solution process [12][13][14] or thermal evaporation, [15] which can lead to local fluctuations in the microstructural features, such as the presence of grain boundaries, [16,17] intragrain defects, [18,19] surfaces, [20,21] and inhomogeneous domain structures. [22,23] These microstructures have a significant effect on recombination, carrier transport, band alignment, and electrical instability. [24] Transmission electron microscopy (TEM), combined with energy-dispersive X-ray spectroscopy (EDS), [25,26] electron energy loss spectroscopy (EELS), [16] cathodoluminescence (CL), [27] and photoluminescence [28] can provide direct and indispensable insights into the structure, composition, andThe ORCID identification number(s) for the author(s) of this article can be found under