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The unfavorable morphology and inefficient utilization of phase transition reversibility have limited the high‐temperature‐processed inorganic perovskite films in both efficiency and stability. Here, a simple soft template‐controlled growth (STCG) method is reported by introducing (adamantan‐1‐yl)methanammonium to control the nucleation and growth rate of CsPbI3 crystals, which gives rise to pinhole‐free CsPbI3 film with a grain size on a micrometer scale. The STCG‐based CsPbI3 perovskite solar cell exhibits a power conversion efficiency of 16.04% with significantly reduced defect densities and charge recombination. More importantly, an all‐inorganic solar cell with the architecture fluorine‐doped tin oxide (FTO)/NiOx/STCG‐CsPbI3/ZnO/indium‐doped tin oxide (ITO) is successfully fabricated to demonstrate its real advantage in thermal stability. By suppressing the inductive effect of defects during the phase transition and utilizing the unique reversibility of the phase transition for the high‐temperature‐processed CsPbI3 film, the all‐inorganic solar cell retains 90% of its initial efficiency after 3000 h of continuous light soaking and heating.

sandwiched between two adjacent organic spacers result in better stability while increasing the bandgap and the exciton binding energy. [3,4] Therefore, a compromised n value around 4 is generally considered as a promising 2D perovskite composition for solar cell application. [5,6] However, the power conversion efficiencies (PCEs) of these 2D perovskite solar cells (PSCs) are substantially lower than those of the 3D PSCs mainly caused by two obstacles: i) in-plane orientation is common for 2D materials due to the minimized surface energy, while the lowconducting organic spacer layers hinder the out-of-plane transport of carriers, leading to a high degree of electrical anisotropy. [7] ii) The over-rapid kinetically controlled self-assembly of 2D perovskite nearly completes its crystallization after the spin-coating process without thermal annealing, which would generate numerous grain boundaries and defective growth. [8] Recent findings offer a range of solutions to address the problem of the highly chaotic system, such as designing new bulky organic ammoniums, [9][10][11][12] adopting the hot-casting technique, [1,6,13] decreasing the precursor supersaturation, [14,15] and applying functional additives, [16][17][18][19] which successfully promote the out-of-plane-oriented growth of 2D perovskite. However, up to now, there is still a lack of attention to the over-rapid crystallization-induced defects in those vertically oriented 2D perovskite films. According to classical nucleation and growth models, film defects are determined by nucleation, coarsening, and coalescence dynamics in establishing the final film morphology. The low nucleation density and retarded crystal growth will encourage the creation of large grains at the crystallization stage and are expected to suppress the effects of boundary defects on both charge transport and recombination kinetics. [20,21] One wellknown example is the film formation of 3D perovskite via solvent annealing. Individual nucleus-centered spots appear on the substrate due to the reduced nucleation density, and the subsequent grain coalescence forms a continuous thin film. This slow crystallization provides longer diffusion distance and self-assembly period of precursor ions/molecules than in all-solid-state thermal annealing to promote the grain growth and yield a high-quality film. [22] Therefore, regulating the nucleation and crystallization dynamics is considered a promising strategy to remove defects from vertically oriented 2D perovskite films, enabling the PCEs of 2D PSCs comparable with those of 3D PSCs.Vertically oriented 2D perovskites exhibit promising optoelectronic properties and intrinsic stability, but their photovoltaic application is still limited by the low power conversion efficiency (PCE) compared to 3D analogs. Here, a new crystallization pathway (RCP) is reported to suppress defects in vertically oriented 2D perovskite caused by its over-rapid self-assembly behavior. By controlling the specific adsorption of an ammonium halide additive on different perovs...

Antimony (Sb) has been identified as a promising candidate for replacing toxic lead (Pb) in perovskite materials because Sb-based perovskite-like halides exhibit not only intrinsic thermodynamic stability but also a unique set of intriguing optoelectronic characteristics. However, Sb-based perovskite-like halides still suffer from poor film morphology and uncontrollable halide constituents, which result from the disorder of the growth process. Herein, we propose a simple strategy to facilitate heterogeneous nucleation and control the dimension transformation by introducing bis­(trifluoromethane)­sulfonimide lithium (LiTFSI), which produces high-quality two-dimensional MA3Sb2I9–x Cl x films. As the spacer molecule among Sb-based pyramidal clusters, LiTFSI plays a role in forming a zero-dimensional intermediate phase and retarding crystallization. The slower dimension transformation well stabilizes the band gap of perovskite-like films with a fixed Cl/I ratio (∼7:2) and avoids random “x” values in MA3Sb2I9–x Cl x films prepared from the conventional method. Based on this method, Sb-based perovskite-like solar cells (PLSCs) achieve the highest recorded power conversion efficiency (PCE) of 3.34% and retain 90% of the initial PCE after being stored under ambient conditions for over 1400 h. More importantly, semitransparent Sb-based PLSCs with PCEs from 2.62 to 3.06% and average visible transparencies from 42 to 23% are successfully obtained, which indicates the great potential of the emerging Pb-free halide semiconductor for broad photovoltaic applications.

3D graphene, as a light substrate for active loadings, is essential to achieve high energy density for aqueous Zn-ion batteries, yet traditional synthesis routes are inefficient with high energy consumption. Reported here is a simplified procedure to transform the raw graphite paper directly into the graphene-like carbon film (GCF). The electrochemically derived GCF contains a 2D-3D hybrid network with interconnected graphene sheets, and offers a highly porous structure. To realize high energy density, the Na:MnO 2 /GCF cathode and Zn/GCF anode are fabricated by electrochemical deposition. The GCF-based Zn-ion batteries deliver a high initial discharge capacity of 381.8 mA h g −1 at 100 mA g −1 and a reversible capacity of 188.0 mA h g −1 after 1000 cycles at 1000 mA g −1 . Moreover, a recorded energy density of 511.9 Wh kg −1 is obtained at a power density of 137 W kg −1 . The electrochemical kinetics measurement reveals the high capacitive contribution of the GCF and a co-insertion/desertion mechanism of H + and Zn 2+ ions. First-principles calculations are also carried out to investigate the effect of Na + doping on the electrochemical performance of layered δ-MnO 2 cathodes. The results demonstrate the attractive potential of the GCF substrate in the application of the rechargeable batteries.

Four carbazole-triphenylamine hole transporting materials (HTMs) with a pyridine or benzene on the N of carbazole have been designed and developed. The molecular structures on their photophysical, electrochemical, thermal, as well as photovoltaic properties in perovskite solar cells (PSCs) are comprehensively analyzed. It is noted that the pyridine-contained compounds show bathochromic spectra response, slightly lower HOMO level, and higher thermal stability than their benzene-contained counterparts. Photoluminescence study indicates that the molecule with a pyridine unit possess better hole extraction properties on the perovskite/HTM interface. When used in PSCs, pyridine-contained HTMs exhibit higher efficiency and better stability than benzene-contained HTMs. Moreover, the PSCs based on the pyridinecontained HTM exhibit a promising power conversion efficiency of 18.45% with good light-soaking and long-term stability, which is even better than that of conventional spiro-OMeTAD under the same conditions. Therefore, the results provide a promising strategy to design and develop novel HTM molecules for efficient and stable PSCs.

Researchers working in the field of photovoltaic are exploring novel materials for the efficient solar energy conversion. The prime objective of the discovery of every novel photovoltaic material is to achieve more energy yield with easy fabrication process and less production cost features. Perovskite solar cells (PSCs) delivering the highest efficiency in the passing years with different stoichiometry and fabrication modification have made this technology a potent candidate for future energy conversion materials. Till now, many studies have shown that the quality of active layer morphology, to a great extent, determines the performance of PSCs. The current and potential techniques of solvent engineering for good active layer morphology are mainly debated using primary solvent, co-solvent (Lewis acid-base adduct approach) and solvent additives. In this review, the dynamics of numerously reported solvents on the morphological characteristics of PSCs active layer are discussed in detail. The intention is to get a clear understanding of solvent engineering induced modifications on active layer morphology in PSC devices via different crystallization routes. At last, an attempt is made to draw a framework based on different solvent coordination properties to make it easy for screening the potent solvent contender for desired PSCs precursor for a better and feasible device.

Elimination of interfacial charge trapping is still a challenge for promoting both efficiency and operational stability of organic–inorganic perovskite solar cells (PSCs). Herein, an effective interface dipole, trimethylamine oxide (TMAO) regarded as a connecting bridge, is inserted between the electron transport layer (ETL) and the perovskite layer to suppress charge accumulation and fabricate highly efficient and stable PSCs. As demonstrated by energy level alignment and morphology characterization, TMAO dipoles could achieve a decreased energetic barrier of electron transport and substantial padding of perovskite in the mesoporous ETL. Thus, they facilitate the charge transfer and reduce trapped charge densities as well as recombination centers at the interface between perovskite and ETL. These desirable properties improve the device efficiency to 21.77% and weaken the hysteresis index almost to 0. More importantly, the stability of the unencapsulated PSCs is remarkably enhanced. The findings provide valuable insights into the role of a dipolar molecule in boosting the performance of PSC devices.