The solvation chemistry of perovskite precursor solutions plays a pivotal role in perovskite crystallization, exerting a significant influence on the performance and stability of devices. As such, the selection of the solvent is of utmost importance. Dimethyl sulfoxide and dimethylformamide, characterized by high Gutmann donor numbers, form strong coordinate bonds with perovskite precursors, thereby retarding perovskite crystallization. Nevertheless, the substantial desolvation activation energy associated with these solvents gives rise to elevated defect concentrations in the resultant perovskite films. In this study, we introduce dimethyl carbonate (DMC), a sustainable solvent with a lower Gutmann donor number that establishes weaker coordination with perovskite precursors. The interactions between DMC and PbI 2 /FAI facilitate the formation of smaller colloidal particles, prolonging the shelf‐life of the precursor solution. Furthermore, the incorporation of DMC enhances the quality of perovskite films, optimizes energy‐level alignment, and improves charge carrier transport and extraction. Consequently, devices treated with DMC exhibit a power conversion efficiency of 25.53%, alongside enhanced long‐term stability.

Hybrid perovskite solar cells (PSCs) suffer from underexplored links between crystallographic orientation and thermal stability, especially in narrow-bandgap devices. We fabricate highly oriented mixed Sn-Pb perovskite films via an additive-free two-step method. Accelerated aging studies at 120°C reveal that high orientation paradoxically compromises stability, and PSCs built from highly oriented perovskite films retain only 73% of their initial power conversion efficiency (PCE), compared to 89% PCE in less-oriented devices. Operando grazing-incidence wide-angle X-ray scattering of the PSCs shows that thermal stress induces significant reorientation and lattice distortion in the oriented crystallites, accumulating pronounced microstrain that accelerates the PSC degradation. Structural analyses confirm progressive crystallographic transitions, including grain reconfiguration, shifts toward isotropy, and systematic diffraction migrations. Critically, we demonstrate that metastability is an intrinsic consequence of high crystallographic order, which is why the very high alignment strategies that enhance performance induce thermodynamic vulnerability. This necessitates redesigning crystal engineering priorities where suppressing instability requires engineering thermodynamic equilibrium states over maximizing alignment for stable perovskite photovoltaics.

Multifunctional Sulfalene additive regulates crystallization dynamics toward inverted perovskite solar cells with enhanced efficiency and stability.

Abstract The planar triple‐layer hole transport layer (HTL)‐free carbon‐based perovskite solar cells have the advantages of low cost and high stability, but their low efficiency hinders the commercialization process. Here, a dual regulation strategy for bulk defects and interface defects has been developed. After selecting dimethylamine (DMA) as the fixed cation and selecting the anion site (I − , Br − , Cl − , HCOO − ), an ionic liquid additive, DMAFo, was synthesized, achieving multiple functions such as energy level regulation, removal of residual PbI 2 at the buried interface, retarding crystallization through the intermediate phase DMAPbI (3−x) HCOO x , filling halide vacancy defects, and releasing residual stress. This effectively reduces energy loss during carrier transport and obtains higher‐quality perovskite films. Under the synergistic effect of DMA + and HCOO − , both bulk defects and interface defects in the perovskite film were simultaneously addressed. The device prepared using DMAFo as an additive achieved the best device efficiency of 20.77%, and after continuous maximum power point tracking for 1200 h, the device efficiency remained almost unchanged, demonstrating excellent operational stability.

With advances in photoelectric conversion efficiency of perovskite solar cells (PSCs), intrinsic instability originating from interfacial defects and residual tensile strain is becoming a great challenge. Herein, a versatile dual-bidentate thiophene-derived molecule, 2,2'-bithiophene-4,4'-dicarboxylic acid (BTDA), is introduced to build a bilateral interface bridge layer for synergistically enabling buried defect passivation and perovskite film strain relaxation. Combined DFT calculations and experimental results verify that the two carboxylic acid groups of BTDA act as precise bilateral grippers to preferentially chelate the uncoordinated Sn4+ upon SnO2, while its thiophene moieties function as deployed bidentate anchoring groups to stabilize the uncoordinated Pb2+ in perovskites. Particularly, the BTDA buried interlayer, as proven by HRTEM, GIXRD, and in situ XPS measurements, induces crystal lattice compression in perovskites beneficial for relaxing the residual tensile strain of the perovskite film and the enhanced thermal stability of the perovskite film. The BTDA-modified PSC yields a boosted power conversion efficiency (PCE) from 21.91% to 24.09% and sustains nearly 80% (unmodified, 57.1%) of its original PCE after 1000 h of aging under ambient conditions (25 °C, 20-50% RH). This work proposes an effective BTDA strategy to concurrently manage bilateral defect passivation and strain relaxation through dual-bidentate anchoring toward efficient and stable PSCs.

In recent years, (4-(3,6-dimethyl-9H-carbazol-9-yl)butyl)phosphonic acid (Me-4PACz) has emerged as a promising interfacial material for wide-bandgap perovskite solar cells (WBG PSCs). However, it suffers from several inherent drawbacks, such as spontaneous aggregation, poor film wettability, low coverage, and weak anchoring to the substrate, which severely compromise interfacial contact between the perovskite and the hole transport layer (HTL), ultimately degrading device performance. In this work, we constructed a co-self-assembled monolayer (Co-SAM) HTL by incorporating pentafluorobenzylphosphonic acid (pFBPA) into Me-4PACz. This strategy not only effectively suppresses the self-aggregation of Me-4PACz but also significantly enhances the hole transport capability of the HTL. Additionally, the interaction between the phosphonic acid groups of pFBPA and PbI2 in the perovskite precursor facilitates controlled nucleation of the perovskite film. Furthermore, the fluorine atoms confer excellent hydrophobicity on the buried perovskite interface. Ultimately, this approach yields a dense, pinhole-free buried perovskite interface along with enhanced crystallinity and moisture resistance of the perovskite layer. The optimized device achieves a power conversion efficiency (PCE) of 20.9% with a high open-circuit voltage (VOC) of 1.36 V. Moreover, the encapsulated device retains 80% of its initial efficiency after 1920 h of storage under ambient conditions (60% relative humidity) and the device retains 80% of the initial PCE after 460 h of maximum power point tracking.

Dual-functional phthalamide modulation of aging-resistant PbI2 for efficient perovskite solar cells.

Tin halide perovskites (THPs) possess remarkably high carrier mobility and absorption coefficient that make them attractive for photosynaptic transistors. However, uncontrollable crystallization kinetics induces 2D/3D phase inhomogeneity and orientation disorder in the perovskite film, ultimately compromising its interfacial quality and device performance. In this work, we address this issue by manipulating interfacial hydrogen bonding through urea modification on SiO2 substrates, resulting in enhanced homogeneity of 2D perovskite phase within the film. Meanwhile, our strategy effectively improves the crystallographic orientation and suppresses defect formation (e.g., Sn4+) toward the buried interface, leading to 5-fold enhancement in field-effect mobility of the transistor. The device exhibits synaptic behaviors under light illumination spanning from visible to near-infrared (NIR) wavelengths, demonstrating synaptic plasticity, paired-pulse facilitation, and learning-forgetting-relearning cycles. This study provides insights toward tailored design of crystallization for high-mobility THP-based transistors and neuromorphic applications.

Tailoring passivators to modulate surface defects of perovskite films represents a pivotal approach to simultaneously improving the optoelectronic properties and long-term operational stability of perovskite solar cells (PSCs). The design of passivators that simultaneously achieve surface passivation and charge extraction is particularly crucial. Herein, we report a dual-site synergistic passivation material, 1-naphthalenethylamine iodide (NEAI1), which is low-cost, structurally simple, and has π-π regulatory effects. It is incorporated into the interfacial passivation layer between the perovskite films and the hole transport layer (HTL). Theoretical calculations show that NEAI1 with naphthalene conjugated structure exhibits stronger electron delocalization ability and larger molecular dipole moment, which can effectively induce interfacial charge transfer. Therefore, NEAI1 showed a champion power conversion efficiency (PCE) of 25.33% and still retained 93.47% of the initial value after storage for about 2200 h, demonstrating excellent device stability. In addition, NEAI1 effectively reduces losses caused by perovskite defects by coordinating with uncoordinated Pb2+ and compensating for iodine vacancies through a dual-site synergistic passivation mechanism.

Blue light-emitting diodes based on reduced-dimensional pure bromide perovskites have attracted increasing attention due to their superiority in achieving stable and efficient blue emissions. Yet, the employment of abundant insulating long-chain organic spacer cations severely limits the charge carriers transport capability and electroluminescence performance. Here, we utilize short-chain iminodi(methylphosphonic acid) ligand with two-terminated phosphonic groups that can strongly interact with the lead bromide octahedra via synergetic covalent bonds, facilitating the interlayer charge transfer and simultaneously reduces the defect density in perovskite films, thereby improving the light emission efficiency. Iminodi(methylphosphonic acid) ligand also enhances the dielectric confinement, leading to higher exciton binding energy and accelerated radiative recombination in perovskite emitters. The resulting blue light-emitting diode achieves a maximum external quantum efficiency of 25.4% and an operational lifetime exceeding 800 min, which represents a significant advancement among state-of-the-art blue light-emitting diodes based on pure bromide perovskites.

Formamidinium lead iodide, FAPbI3 (FA+ = CH(NH2)2+), with a cubic perovskite structure is among the most studied organic-inorganic hybrid perovskites. Despite several reports only on thin films of FA-rich lead iodide perovskites, such as FA2PbI4, their structures remain unknown due to challenges in characterizing polycrystalline films. Here, we report two new phases of FA-rich lead iodide perovskite-derived structures, FA2PbI4 and FA3PbI5, in the bulk form. These materials feature two- and one-dimensional octahedral networks of perovskite, respectively, allowing for bandgap tuning among FA-Pb-I compositions. This study presents a novel approach to controlling the structural dimensionality of perovskites and their optical properties.

Perovskite solar cells (PSCs) have demonstrated substantial potential due to their superior optoelectronic performance, but rapid and often poorly controlled crystallization during dynamic solution processing frequently leads to defective crystal growth and compromised film quality. Herein, we introduce a strategy utilizing polar polymers to intricately regulate solvent polarity and evaporation kinetics, thereby modulating the dynamics of perovskite crystallization. Particularly, the strongly polarized, high-population fluorinated groups in poly(pentafluorostyrene) strongly interact with solvent molecules in the precursor solution, stabilizing the solvent-containing intermediate phase and controlling the exfoliation of solvent molecules during perovskite crystallization. Direct imaging by scanning transmission electron microscopy reveals the structure of the intermediate phase, and in situ optical studies demonstrate that the regulated crystallization suppresses defect formation and improves film quality. Consequently, inverted PSCs fabricated via this new solvent engineering strategy achieve an efficiency of 26.4% and retain 92% after 1000 h of continuous illumination, underscoring the effectiveness of this strategy of polarizing the solvent.

Tin fluoride (SnF2) serves as an indispensable antioxidant in Sn-Pb perovskite solar cells, playing a critical role in the development of efficient all-perovskite tandem architectures. However, excessive SnF2 often suffers from aggregation challenges, inevitably causing phase separation and tensile strain within the perovskite films, severely compromising device efficiency and stability. In this study, we report a precise regulation strategy by employing phenylethylammonium chloride (PEACl) to modulate the distribution of excess SnF2. The hydrogen bonding between PEACl and SnF2, coupled with steric hindrance effects, enables uniform dispersion of SnF2 at grain boundaries, effectively suppressing SnF2 phase segregation and promoting homogeneous crystallization of Sn-Pb perovskites. Moreover, it is revealed that the precise regulation of SnF2 distribution through PEACl effectively releases local strain in perovskite thin films. Single-junction Sn-Pb devices treated with the SnF2+PEACl demonstrate an exceptional power conversion efficiency (PCE) of 23.52%, substantially outperforming control devices at 20.83%. The optimized two-terminal (2-T) monolithic all-perovskite tandem solar cells achieve a remarkable PCE of 28.89%. Notably, these tandem devices maintain over 80% of their initial efficiency after continuous operation at maximum power point under one-sun illumination for 670h, exhibiting excellent long-term stability.

Low-pressure chemical vapor deposition (CVD) offers good scalability, substrate compatibility, and solvent-free processing for metal halide perovskite films fabrication, yet limited control over the film composition has hindered the device performance compared to solution-based methods. Herein, we investigate how the substrate surface property affect the composition and optoelectronic properties of perovskite films fabricated by CVD. By changing the hole transporting layers (HTLs), different crystallization process and chemical stoichiometry of perovskite films have been observed. Perovskite films grown on nickel oxide|self-assembled monolayers (SAMs) exhibit a more stoichiometric buried surface, along with a higher work function (WF) and enhanced p-type character that are favorable for hole transport. Leveraging these insights, we demonstrate all vapor-deposited semitransparent perovskite solar cells (ST-PSCs) with a champion efficiency of 18.0%, retaining ∼100% of the initial performance after 500 h of continuous operation (ISOS-L-1). Furthermore, we achieve a champion efficiency of 17.5% for semitransparent mini-modules fabricated via the all-vacuum process.

Perovskite solar cells (PSCs) have emerged as a promising photovoltaic technology, offering outstanding power conversion efficiency and significant potential for large-scale deployment. However, during printed fabrication, the intrinsic coffee-ring effect induces heterogeneous deposition of colloidal particles, leading to non-uniform crystallization that critically limits the performance of large-area devices. This issue not only complicates the crystallization dynamics of perovskite films but also impedes the development of a universal fluidic control strategy applicable across device scales. In this work, we harnessed the mechanisms of coffee-ring formation and employed rapid drying combined with droplet fragmentation to construct a size-tunable flow-locking network at the buried interface. This network effectively confines the disordered migration of perovskite colloidal particles throughout the flowing and drying stages, suppressing the formation of macroscopic coffee rings and mitigating their detrimental impact on device crystallization and performance. As a result, the optimized PSCs deliver a high power conversion efficiency (PCE) of 26.61%, while a large-area module (100 cm2) maintains an impressive PCE of 21.39%, demonstrating excellent scalability and device uniformity.

Perovskite solar cells (PSCs) have become a highly promising photovoltaic technology, which can be attributed to their distinctive advantages. The quality of the perovskite thin films plays a crucial role in determining the photovoltaic performance of PSCs. Ionic liquids (ILs) have demonstrated efficacy in passivating defects within perovskite thin films. However, certain aspects remain inadequately addressed, particularly the microscopic interaction mechanisms between ILs and perovskites. In this study, a long-chain functionalized IL (VC12ImBr) was developed as an effective regulatory material for preparation of high-performance perovskite films and devices in air. The mechanism by which VC12ImBr affects the optoelectronic properties of perovskite films and devices has been elucidated through an integration of theoretical simulations and a range of in situ experimental characterization techniques. In situ characterization revealed that VC12ImBr precisely regulates the crystallization process of perovskite, effectively passivating the film defects and achieving high-quality perovskite films. Ultimately, the power conversion efficiency (PCE) of the device modified with VC12ImBr prepared in air was effectively improved by about 15% with superior long-term stability.

The inverted perovskite solar cell (PSC), featuring self-assembled monolayers (SAMs) as the hole transport layer, has achieved a power conversion efficiency (PCE) exceeding 27%. However, the non-uniformity of SAMs and intrinsic defects within the perovskite film continue to constrain further enhancements in device performance. Herein, we developed a strategy for the synchronous modification of SAMs and perovskite by incorporating an ionic liquid of 1-butyl-3-methylimidazole-hexafluorophosphate (BM) to enhance the uniformity of SAMs and passivate defects in perovskite. Specifically, BM was incorporated into the perovskite precursor solution to effectively occupy halide vacancies and passivate the uncoordinated Pb2+. Meanwhile, owing to its ionic properties and the interaction between its functional groups and SAM, BM can effectively regulate the colloidal properties and reduce surface roughness, achieving a more uniform SAM layer. By employing this dual modification strategy, BM significantly modulates the crystallization kinetics, thereby facilitating the formation of highly crystalline perovskite films characterized by substantially enlarged grain sizes and a markedly reduced defect density. Consequently, the device incorporating dual modification of BM achieved a champion PCE of 26.59%, demonstrating exceptional operational stability with no observable PCE degradation after continuous power output at maximum power point (MPP) for 1000h.

Perovskite Light-Emitting Diodes (PeLEDs) hold significant promise for future applications in displays due to their exceptional optoelectronic properties. However, the complexity of the crystallization process during the preparation of metal halide perovskite often leads to morphological inhomogeneity, defect-mediated non-radiative recombination losses, and subsequent performance degradation in devices. A profound understanding of perovskite nucleation and crystallization dynamics is crucial for fabricating high-performance PeLEDs. Based on this premise, this review systematically summarizes advanced strategies for regulating perovskite crystallization kinetics, which are grouped into two approaches: regulating nucleation sites to achieve dense and uniform perovskite films, and delaying crystal growth to enlarge grain size and suppress defect-mediated non-radiative recombination losses. In addition, this review examines the current challenges facing future full-color displays and large-scale production in PeLEDs. Finally, we outline promising future research directions, including the development of machine learning, and scalable fabrication techniques such as blade coating and inkjet printing, to bridge the gap between laboratory research and commercial applications. This review aims to provide comprehensive theoretical and practical insights into perovskite crystallization optimization, thereby accelerating the commercialization of PeLED technology.

Perovskite solar cells (PSCs) are susceptible to environmental factors such as humidity and heat. Here, a mixed-ligand zeolitic imidazolate framework (ML-ZIF) synthesized by partially replacing the 2-methylimidazole (2-MIM) ligand in ZIF-8 with 2-mercaptoimidazole (2-MeIM) is introduced into a perovskite film as a multifunctional additive, which simultaneously modulates the crystallization of perovskite, passivates the bulk phase defects and enhances the damp-heat stability of the devices. In particular, the thiol groups in 2-MeIM strongly coordinate with undercoordinated Pb2+ ions at grain boundaries, effectively reducing the density of non-radiative recombination centers. Finally, the optimal ML-ZIF doped PSCs yield a high power conversion efficiency (PCE) of 24.12%, outperforming the control device (21.52%). The enhanced hydrophobicity and thermal conductivity imparted by ML-ZIF doping enable the devices to retain over 90% of their initial PCE after 700 hours at 65% relative humidity and 200 hours at 80 °C, respectively. Consequently, the incorporation of ML-ZIF presents a promising strategy to concurrently address the efficiency and stability challenges, thereby advancing the commercial prospects of PSCs.

Wide-bandgap (1.68 eV) perovskite solar cells (PSCs) are considered promising candidates for indoor photovoltaics due to their favorable optical properties. However, their power conversion efficiency (PCE) is significantly constrained by large open-circuit voltage (VOC) losses, which primarily originate from intrinsic halide vacancy defects and uncoordinated Pb2+ located at the surface and grain boundaries of the perovskite films. Additionally, the energy level mismatches at the perovskite/electron transport layer (ETL) interface further aggravate VOC losses by promoting nonradiative recombination. Herein, we report a synergistic dual-halide interface passivation strategy based on methylammonium iodide (MAI) and methylammonium chloride (MACl), in which the two halides play complementary and mechanistically distinct roles. MAI effectively reacts with and converts residual surface PbI2 into the perovskite phase, while simultaneously passivating iodine-related vacancy defects. In parallel, MACl induces beneficial chloride incorporation at the interface, enabling slight bandgap broadening and producing a favorable vacuum-level shift that optimizes energy-level alignment between the perovskite and electron transport layer. When applied together, MAI and MACl deliver a cooperative passivation effect, substantially suppressing nonradiative recombination, prolonging carrier lifetimes, and facilitating more efficient charge extraction. As a result, the optimized 1.68 eV PSCs achieve a notable PCE of 20.41% with a VOC of 1.262 V under standard AM 1.5G illumination, surpassing the untreated counterparts that achieve 18.48% with a VOC of 1.169 V. More importantly, under indoor lighting conditions, the modified PSCs exhibit outstanding performance, delivering PCEs of 36.74 and 32.36% under 1000 and 200 lx LED illumination, respectively, demonstrating their strong potential for indoor photovoltaics.