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The realization of efficient large-area perovskite solar cells stands as a pivotal milestone for propelling their future commercial viability. However, the upscaling fabrication of perovskite solar cells is hampered by efficiency losses, and the underlying growth mechanism remains enigmatic. Here, it is unveiled that a prevalent upscaling technology, namely blade-coating, inherently triggers top-down inhomogeneity strains, predominantly concentrated on the surface of wide-bandgap perovskite films. Through strain mitigation strategies, the perovskite films exhibit reduced halide vacancies, leading to enhanced stability and improved optoelectronic characteristics. Consequently, the blade-coated perovskite solar cells achieve minimal efficiency loss when transitioning from small-area to large-area devices, enabling the realization of 1 cm²-area 1.77 eV-bandgap cells with a remarkable efficiency of 18.71%. Additionally, the strain-relieved device exhibits an exceptional 109% retention of its initial efficiency even after 400 h of continuous operation, in stark contrast to the control device which experiences a decline to 91%. Furthermore, the resulting 4-terminal all-perovskite tandem solar cells crafted utilizing blade-coated 1.77 eV-bandgap subcells achieve a maximum efficiency of 27.64% (stabilized at 27.28%). This study not only sheds light on the intricacies of upscaling preparation techniques but also overcomes potential obstacles that can impede the trajectory toward achieving large-scale perovskite solar cells. [ABSTRACT FROM AUTHOR]

Perovskites are promising light emitters that can cover broad-range emissions over the entire visible spectrum. However, few studies have focused on uncommon wavebands, such as far-red emission of 700-750 nm that has broad applications in biology, horticulture lighting, optogenetics, etc. Here, a strategy is demonstrated to achieve high-performance far-red perovskite light-emitting diodes (PeLEDs) through antisolvent engineering. First, 1,3,5-tris(1-phenyl-1H-benzimidazole-2-yl) benzene (TPBi) is introduced into n-i-p perovskite matrix not only to passivate the defects but also to balance carrier mobility as well as adjust the energy level alignment between perovskite and the electron transport layer. The n-type TPBi can prevent hole carriers' movements in perovskite light emitters and enhance electron injection. Furthermore, the incorporation of TPBi uplifts the Fermi energy level of perovskites by 0.32 eV as well as diminishes the conduction band offset between zinc oxide (ZnO) and the perovskite emitters, hence alleviating the accumulation of charges at the interface. Consequently, the PeLEDs with TPBi-modified perovskite emitters show an invariable far-red emission peak at around 735 nm with a champion external quantum efficiency of 14.22%. This work makes up the far-red emission of perovskite light-emitting devices and boosts latent capacity of PeLEDs for future application. [ABSTRACT FROM AUTHOR]