Metal halide perovskite solar cells (PSCs) are promising as the next-generation photovoltaic technology. However, the inferior stability under various temperatures remains a significant obstacle to commercialization. Here, a heat-triggered dynamic self-healing framework (HDSF) is implemented to repair defects at grain boundaries caused by thermal variability, enhancing PSCs' temperature stability. HDSF, distributed at the grain boundaries and surface of the perovskite film, stabilizes the perovskite lattice and releases the perovskite crystal stress through the dynamic exchange reaction of sulfide bonds. The resultant PSCs achieved a power-conversion efficiency (PCE) of 26.32% (certified 25.84%) with elevated temperature stability, retaining 88.7% of the initial PCE after 1000 h at 85 °C. In a variable temperature cycling test (between -40 and 80 °C), the HDSF-treated device retained 87.6% of its initial PCE at -40 °C and 92.6% at 80 °C after 160 thermal cycles. This heat-triggered dynamic self-healing strategy could significantly enhance the reliability of PSCs in application scenarios.

Tin-based perovskite solar cells offer a less toxic alternative to their lead-based counterparts. Despite their promising optoelectronic properties, their performances still lag behind, with the highest power conversion efficiencies reaching around 15%. This efficiency limitation arises primarily from electronic defects leading to self-p-doping and stereochemical activity of the Sn(II) ion, which distorts the atomic arrangement in the material. In this study, we investigate the effect of strontium doping in tin-based perovskite on the distortion of the material's structure and its optoelectronic properties. Using a combination of Density Functional Theory calculations and experiments, we demonstrate that strontium doping reduces p-doping and structural strain. This approach improves the efficiency from 6.3% in undoped devices to 7.5% in doped devices without relying on dimethyl sulfoxide, a harmful solvent for tin-based perovskites. This method could enable precise control of tin off-centering and self-p-doping, advancing the development of efficient and stable tin perovskite solar cells.

Mixed tin-lead (Sn-Pb) perovskites have attracted the attention of the community due to their narrow bandgap, ideal for photovoltaic applications, especially tandem solar cells. However, the oxidation and rapid crystallization of Sn2+ and the interfacial traps hinder their development. Here, cross-linkable [6,6]-phenyl-C61-butyric styryl dendron ester (C-PCBSD) is introduced during the quenching step of perovskite thin film processing to suppress the generation of surface defects at the electron transport layer interface and improve the bulk crystallinity. The C-PCBSD has strong coordination ability with Sn2+ and Pb2+ perovskite precursors, which retards the crystallization process, suppresses the oxidation of Sn2+, and improves the perovskite bulk and surface crystallinity, yielding films with reduced nonradiative recombination and enhanced interface charge extraction. Besides, the C-PCBSD network deposited on the perovskite surface displays superior hydrophobicity and oxygen resistance. Consequently, the devices with C-PCBSD obtain PCEs of up to 23.4% and retained 97% of initial efficiency after 2000 h of storage in a N2 atmosphere.

Tin halide perovskite solar cells are promising for the next generation of highly efficient photovoltaics. Their commercialization can be accelerated by increasing their stability in moisture and oxygen. Herein, an n‐type organic molecule (IO‐4Cl) is applied as an interlayer between the perovskite films and electron transport layers in p‐i‐n structured devices. The electron‐rich indacenodithieno‐[3,2‐b]thiophene enhances electron transport, while the hydrocarbon side chains and rigid conjugated backbone isolate air. It is also shown that the C═O in IO‐4Cl can coordinate with Sn 2+ on perovskite films' surface and grain boundaries to enhance perovskite crystal stability. In addition, IO‐4Cl slows down crystallization dynamics, resulting in lower non‐radiation recombination. The moisture ingress in the perovskite films is tracked under high relative humidity (RH) and it is found that IO‐4Cl can mitigate moisture infiltration. Finally, the devices with IO‐4Cl maintain 95% of the initial power conversion efficiency after 1200 h of storage in a nitrogen‐filled glovebox, and their stability in ambient air (60–80% RH) is significantly improved against pristine devices, thus demonstrating the beneficial effects of IO‐4Cl interlayer on device stability.

Metal halide perovskites, an emerging photovoltaic material, have attracted significant attention in the industry and academia due to their excellent optoelectronic properties. However, perovskite solar cells' (PSCs) stability has become the biggest obstacle to commercialization despite the progress in their commercial development. Interface engineering, doping, and novel charge-transport materials are effective approaches to enhance the stability of PSCs. Since discovering graphene as a single-layer material, researchers have favored two-dimensional (2D) materials for their outstanding physical and chemical properties. In the continuous development of PSCs, 2D materials offer tunable functional groups, tunable energy levels, high charge transfer capabilities, and extraordinary physical characteristics such as thermal conductivity and hydrophobicity. They serve as effective materials to improve the stability of PSCs. Different types of 2D materials may exhibit unprecedented effects through different functional designs. In this review, the specific mechanisms through which 2D materials enhance the stability of perovskite solar cells (PSCs) are focused on and recent advancements in improving PSC stability across various dimensions are summarized, including photo, thermal, and environmental stability, and the potential applications of different types of 2D materials are discussed. Finally, insights are offered into addressing stability-related challenges in PSCs. This comprehensive approach aims to guide future research efforts in optimizing both the stability and performance of PSCs through the integration of 2D materials.

All-inorganic quantum dot (QD) light-emitting diodes (AI-QLEDs) with excellent stability received enormous interest in the past few years. Nevertheless, the vast energy offset and the high trap density at the NiOX/QDs interface limit hole injection leading to fluorescence quenching and hampering the performance. Here, we present self-assembled monolayers (SAMs) with phosphonic acid (PA) anchoring groups modifying NiOX hole transport layer (HTL) to tune energy level and passivate trap states. This strategy facilitates hole injection owning to the well-aligned energy level by interface dipole, downshifting the vacuum level, reducing the hole injection barrier from 0.94eV to 0.28eV. Meanwhile, it mitigates the interfacial recombination by passivating surface hydroxyl group (-OH) and oxygen vacancy (VO) traps in NiOX. The electron leakage from QDs toward NiOX HTL is significantly suppressed. The all-inorganic R-QLEDs exhibit one of the highest maximum luminance, external quantum efficiency and operational lifetime of 88980cdm−2, 10.3% and 335045h (T50@100cdm−2), respectively. The as-proposed interface engineering provides an effective design principle for high-performance AI-QLEDs for future outdoor and optical projection-type display applications.

The tunable bandgaps of metal halide perovskites lead to their promising application in indoor photovoltaics (IPVs). However, perovskites with wide bandgaps suitable for indoor light typically have lower conductivity and higher defect density, which leads to inefficient charge transport and extraction, limiting their photovoltaic performances. Herein, we investigated the IPV characteristics of triple-cation perovskites with varying bandgaps by tailoring the Br/I ratios. We found that wide-bandgap perovskites could effectively utilize indoor light and achieve high open circuit voltage values under low illumination conditions. However, increasing the Br/I ratios results in higher defect density, leading to decreased short-circuit current density and fill factor. We thoroughly studied the crystallization dynamics, defect density, and charge transfer properties of triple-cation perovskites with varying bandgaps. We found the prevailing concept that efficient IPVs taking the bandgap of IPV materials into special consideration was not comprehensive. We demonstrate that IPV devices with superior IPV properties can be developed by appropriately reducing the Br contents in wide-bandgap crystals. In other words, the preparation of IPV crystal materials should consider both the bandgap and charge transport characteristics. In this work, we obtained devices with the optimal efficiency of 40.71

Interface-induced nonradiative recombination losses at the perovskite/electron transport layer (ETL) are an impediment to improving the efficiency and stability of inverted (p-i-n) perovskite solar cells (PSCs). Tridecafluorohexane-1-sulfonic acid potassium (TFHSP) is employed as a multifunctional dipole molecule to modify the perovskite surface. The solid coordination and hydrogen bonding efficiently passivate the surface defects, thereby reducing nonradiative recombination. The induced positive dipole layer between the perovskite and ETLs improves the energy band alignment, enhancing interface charge extraction. Additionally, the strong interaction between TFHSP and the perovskite stabilizes the perovskite surface, while the hydrophobic fluorinated moieties prevent the ingress of water and oxygen, enhancing the device stability. The resultant devices achieve a power conversion efficiency (PCE) of 24.6%. The unencapsulated devices retain 91% of their initial efficiency after 1000 h in air with 60% relative humidity, and 95% after 500 h under maximum power point (MPP) tracking at 35 °C. The utilization of multifunctional dipole molecules opens new avenues for high-performance and long-term stable perovskite devices.

Tin perovskites are the most promising environmentally friendly alternative to lead perovskites. Among tin perovskites, FASnI3 (CH4N2SnI3) shows optimum band gap, and easy processability. However, the performance of FASnI3 based solar cells is incomparable to lead perovskites for several reasons, including energy band mismatch between the perovskite absorber film and the charge transporting layers (CTLs) for both types of carriers, i.e., for electrons (ETLs) and holes (HTLs). However, the band diagrams in the literature are inconsistent, and the charge extraction dynamics are poorly understood. In this paper, we study the energy band positions of FASnI3 based perovskites using Kelvin probe (KP) and photoelectron yield spectroscopy (PYS) to provide a precise band diagram of the most used device stack. In addition, we analyze the defects within the current energetic landscape of tin perovskites. We uncover the role of bathocuproine (BCP) in enhancing the electron extraction at the fullerene C60/BCP interface. Furthermore, we used transient surface photovoltage (tr-SPV) for the first time for tin perovskites to understand the charge extraction dynamics of the most reported HTLs such as NiOx and PEDOT, and ETLs such as C60, ICBA, and PCBM. Finally, we used Hall effect, KP, and time-resolved photoluminescence (TRPL) to estimate an accurate value of the p-doping concentration in FASnI3 and showed a consistent result of 1.5 * 1017 cm-3. Our findings prove that the energetic system of tin halide perovskites is deformed and should be redesigned independently from lead perovskites to unlock the full potential of tin perovskites.

Tin halide perovskites are an appealing alternative to lead perovskites. However, owing to the lower redox potential of Sn(II)/Sn(IV), particularly under the presence of oxygen and water, the accumulation of Sn(IV) at the surface layer will negatively impact the device's performance and stability. To this end, this work has introduced a novel multifunctional molecule, 1,4-phenyldimethylammonium dibromide diamine (phDMADBr), to form a protective layer on the surface of Sn-based perovskite films. Strong interactions between phDMADBr and the perovskite surface improve electron transfer, passivating uncoordinated Sn(II), and fortify against water and oxygen. In situ grazing incidence wide-angle X-ray scattering (GIWAXS) analysis confirms the enhanced thermal stability of the quasi-2D phase, and hence the overall enhanced stability of the perovskite. Long-term stability in devices is achieved, retaining over 90% of the original efficiency for more than 200 hours in a 10% RH moisture N2 environment. These findings propose a new approach to enhance the operational stability of Sn-based perovskite devices, offering a strategy in advancing lead-free optoelectronic applications.

Daily temperature variations induce phase transitions and lattice strains in halide perovskites, challenging their stability in solar cells. We stabilized the perovskite black phase and improved solar cell performance using the ordered dipolar structure of β-poly(1,1-difluoroethylene) to control perovskite film crystallization and energy alignment. We demonstrated p-i-n perovskite solar cells with a record power conversion efficiency of 24.6% over 18 square millimeters and 23.1% over 1 square centimeter, which retained 96 and 88% of the efficiency after 1000 hours of 1-sun maximum power point tracking at 25° and 75°C, respectively. Devices under rapid thermal cycling between −60° and +80°C showed no sign of fatigue, demonstrating the impact of the ordered dipolar structure on the operational stability of perovskite solar cells.

Due to its outstanding optoelectronic properties, halide perovskite solar cells (PSCs) power conversion efficiency has rapidly grown to 25.7%. Nonetheless, lead poisoning is a significant hurdle to the deployment of perovskite solar cells (PSCs). Tin is the most alternative with the most potential due to its similar electric and electronic properties to lead and its less hazardous nature. Yet, the performance of Sn-based PSCs lags significantly below that of Pb-based PSCs due to the Sn (II)'s easy oxidation to Sn (IV). Incorporating large-sized organic cations to form quasi-two-dimensional (2D) structured-tin perovskites increases the stability of the PSC. In addition, the hydrophobic group of the quasi-2D structure inhibits moisture and oxygen from penetrating the absorber layers. This review analyzes and evaluates the characteristics and performance of quasi-2D Sn-based perovskites such as Ruddlesden-Popper, Dion-Jacobson, and alternating cation interlayer (ACI). This work further proposes alternative strategies to improve the efficiency and stability of tin-based PSCs, including constructing new mixed 2D/3D perovskite structures, enhancing the transmission capacity, novel organic cations, and fabricating new ACI perovskite structures and controlling perovskite strain.

Perovskite materials have attracted much attention in various optoelectronics applications such as solar cells, light-emitting diodes, and photodetectors. Compared to multicrystalline films, single crystal perovskites are free of grain boundaries and exhibit lower defect density, longer carrier lifetimes, longer carrier diffusion distances, and outstanding stability, thus having the potential to show superior performances in optoelectronic devices. In addition, single crystal nanostructures are ideal model systems for studying the fundamental optoelectronic properties of newly designed functional materials. This review provides a thorough introduction to the fundamental theories behind crystal nucleation and growth. In addition, we provide an in-depth analysis of the application of classic ideas to the experimental formation of perovskite crystals including inorganic and hybrid halide perovskites with low dimensional and three-dimensional structures. Subsequently, we correlate the crystal structure and optoelectronic properties and summarize the recent advances in the application of perovskite single crystals in various optoelectronic devices. Finally, we discuss the ongoing challenges in single crystal growth and the emerging optoelectronic applications. This review will serve as a valuable resource for future studies on the synthesis and uses of perovskite single crystals.

Blue quantum dot (QD) light-emitting diodes (QLEDs) exhibit unsatisfactory operational stability and electroluminescence (EL) properties due to severe nonradiative recombination induced by large numbers of dangling bond defects and charge imbalance in QD. Herein, dipolar aromatic amine-functionalized molecules with different molecular polarities are employed to regulate charge transport and passivate interfacial defects between QD and the electron transfer layer (ETL). The results show that the stronger the molecular polarity, especially with the -CF3 groups possessing a strong electron-withdrawing capacity, the more effective the defect passivation of S and Zn dangling bonds at the QD surface. Moreover, the dipole interlayer can effectively reduce electron injection into QD at high current density, enhancing charge balance and mitigating Joule heat. Finally, blue QLEDs exhibit a peak external quantum efficiency (EQE) of 21.02% with an operational lifetime (T50 at 100 cd m-2) exceeding 4000 h.

Herein, we report highly efficient and stable triple cation perovskite solar cells (PSCs) with the structure of FTO/TiO2/perovskite/spiro-OMeTAD/Ag, in which we introduce aminophylline (APL) as an additive into the perovskite precursor solution to improve efficiency and stability. The APL additive results in increased device current density (J(SC)) (23.07-23.86 mA/cm(2)), fill factor (FF) (77.9-81.82%) and open-circuit voltage (V-OC) (1.09-1.13 V), leading to an improved power conversion efficiency (PCE) of 22.11% compared to control devices (19.62%). It is worth noting that unpackaged devices employing the APL additive can remain 60% of their initial PCE in the air (at a humidity of 25-30%) after 100 days, whereas control devices merely retain less than 14% of the initial efficiency.

Due to their outstanding optoelectronic properties, lead-based halide perovskite materials have been applied as efficient photoactive materials in solution-processed solar cells. Current record efficiencies offer the promise to surpass those of silicon solar cells. However, uncertainty about the potential toxicity of lead-based halide perovskite materials and their facile dissolution in water requires a search for new alternative perovskite-like materials. Thanks to the foresight of scientists and their experience in lead-based halide perovskite preparation, remarkable results have been obtained in a short period of time using lead-free perovskite compositions. However, the lower solar-to-energy conversion efficiency and long-term stability issues are serious drawbacks that hinder the potential progression of these materials. Here, we review and analyse strategies in the literature and the most promising solutions to identify the factors that limit the power conversion efficiency and long-term stability of lead-free tin-based perovskite solar cells. In the light of the current state-of-the-art, we offer perspectives for further developing these promising materials.

The power conversion efficiency of the formamidinium tin iodide (FASI) solar cells constantly increases, with the current record power conversion efficiency approaching 15%. The literature reports a broad anomaly distribution of the photoluminescence (PL) peak position. The PL anomaly is particularly relevant to photovoltaic applications since it directly links the material's bandgap and subgap defects energy, which are crucial to extracting its full photovoltaic potential. Herein, the PL of FASI polycrystalline thin film and powder is studied. It is found that a distribution of PL peak positions in line with the distribution available in the literature systematically. The distribution in PL is linked to the octahedral tilting and Sn off‐centering within the perovskite lattice, influenced by the procedure used to prepare the material. Our finding paves the way toward controlling the energy distribution of tin perovskite and thus preparing highly efficient tin halide perovskite solar cells.

Controlling the crystallization of perovskite in a thin film is essential in making solar cells. Processing tin-based perovskite films from solution is challenging because of the uncontrollable faster crystallization of tin than the most used lead perovskite. The best performing devices are prepared by depositing perovskite from dimethyl sulfoxide because it slows down the assembly of the tin-iodine network that forms perovskite. However, while dimethyl sulfoxide seems the best solution to control the crystallization, it oxidizes tin during processing. This work demonstrates that 4-(tert-butyl) pyridine can replace dimethyl sulfoxide to control the crystallization without oxidizing tin. We show that tin perovskite films deposited from pyridine have a 1 order of magnitude lower defect density, which promotes charge mobility and photovoltaic performance.

This dataset is a CSV snapshot of The Perovskite Database available at www.perovskitedatabase.com.