long carrier diffusion lengths, adjustable bandgaps, and low-cost fabrication. [1][2][3] Until now, the certified power conversion efficiency (PCE) has reached 25.5%, [4] making the PSC a promising candidate for the next-generation thin-film solar cells. [3,5] However, the presently obtained record PCE is still far from Shockley-Queisser limit efficiency. [6] In addition, the currently achieved stability is much lower below the standard of commercial application. It is well known that poor perovskite film quality is one of the main reasons for efficiency and stability losses. Consequently, it is highly expected to minimize the trap-assisted nonradiative recombination losses via improving perovskite film quality.The traditional solution method with fast crystallization and high-temperature annealing process would inevitably lead to a variety of defects in perovskite bulk and at the surfaces and grain boundaries (GBs). [7][8][9] Most defects in the bulk of perovskite films are shallow-level defects, while most defects at the surface and GBs of perovskite films are deep-level defects, which is detrimental to device performance through capturing carriers. [6,10,11] Moreover, these defects would provide pathways for ion migration, which results in efficiency and stability losses. [6,12,13] In addition, water and oxygen would preferentially attack the surface and GBs of perovskiteThe nonradiative recombination losses resulting from the trap states at the surface and grain boundaries directly hinder the further enhancement of power conversion efficiency (PCE) and stability of perovskite solar cells. Consequently, it is highly desirable to suppress nonradiative recombination through modulating perovskite crystallization and passivating the defects of perovskite films. Here, a simple and effective multifunctional additive engineering strategy is reported where 11 Maleimidoundecanoic acid (11MA) units with carbonyls (carboxyl and amide) and long hydrophobic alkyl chain are incorporated into a perovskite precursor solution. It is revealed that improved crystallinity, reduced trap state density, and inhibited ion migration are achieved, which is ascribed to the strong coordination interaction between the carbonyl groups at both sides of 11MA molecules and Pb 2+ . As a result, improved efficiency and stability are achieved simultaneously after introducing 11MA additive. The device with 11MA additive delivers a champion PCE of 23.34% with negligible hysteresis, which is significantly higher than the 18.24% of the control device. The modified device maintains around 91% of its initial PCE after aging under ambient conditions for 3000 h. This work provides a guide for developing multifunctional additive molecules for the purpose of simultaneous improvement of efficiency and stability.

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Perovskite solar cells (PSCs) have had a lasting impression on the scientific community because of their fast progress as high efficient and low-cost technology. [1] Starting from Kojima et al., in 2009, maximum power conversion efficiencies (PCEs) exceeding 25% have already been certified, resulting from crystallinity optimization, [2,3] morphology control, [4] interface engineering, [5,6] and defects passivation. [3,7,8] Several methods have been reported to prepare high-quality perovskite films, including thermal evaporation, twostep sequential deposition, vapor-assisted solution processing, and one-step spincoating method. [9] Although the simple, antisolvent-free, low-toxic, and time-consuming two-step method has been widely used in most of the high-efficiency PSCs with certified PCE exceeding 24%, [10][11][12] the quickly transformed perovskite often exhibit poor surface coverage with pinholes and high surface roughness, [13] which is related to the rapid reaction between the PbI 2 and the organic component (FAI, MABr, MACl, etc.). [14] More importantly, the polycrystalline perovskite usually contains a large number of structural disorders [15] and surface defects, [16] inducing severe degradation of photovoltaic performance. Defect inhibition in perovskite absorbers for enabling further photovoltaic and stability enhancement is still sluggish. Additive engineering by small molecule, inorganic salt, Lewisbased additives has been developed to control the crystallinity and surface defects in PSCs. [3,[17][18][19] Nevertheless, most of the additives are non-ABX 3 perovskite component units, so it is inevitable to introduce impurities. In particular, ionic liquids (ILs), which usually contain organic cations and pseudohalogen anions, are regarded as the ideal passivation materials for

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Metal organic frameworks (MOFs) derivatives have received extensive attentions in the field of microwave absorption due to their unique advantages and various properties. In this work, cubic hollow CoNi/C composites...

Interfacial nonradiative recombination loss is a huge barrier to advance the photovoltaic performance. Here, one effective interfacial defect and carrier dynamics management strategy by synergistic modulation of functional groups and spatial conformation of ammonium salt molecules is proposed. The surface treatment with 3‐ammonium propionic acid iodide (3‐APAI) does not form 2D perovskite passivation layer while the propylammonium ions and 5‐aminopentanoic acid hydroiodide post‐treatment lead to the formation of 2D perovskite passivation layers. Due to appropriate alkyl chain length, theoretical and experimental results manifest that COOH and NH3+ groups in 3‐APAI molecules can form coordination bonding with undercoordinated Pb2+ and ionic bonding and hydrogen bonding with octahedron PbI64−, respectively, which makes both groups be simultaneously firmly anchored on the surface of perovskite films. This will strengthen defect passivation effect and improve interfacial carrier transport and transfer. The synergistic effect of functional groups and spatial conformation confers 3‐APAI better defect passivation effect than 2D perovskite layers. The 3‐APAI‐modified device based on vacuum flash technology achieves an alluring peak efficiency of 24.72% (certified 23.68%), which is among highly efficient devices fabricated without antisolvents. Furthermore, the encapsulated 3‐APAI‐modified device degrades by less than 4% after 1400 h of continuous one sun illumination.