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Antisolvent engineering is one of the most useful strategies to get high-efficiency perovskite solar cells (PSCs). Nevertheless, the most present commonly used effective antisolvents, such as chlorobenzene and diethyl ether, are toxic and expensive. Moreover, these antisolvents applied in PSCs are rather restricted due to their narrow processing window. Herein, we report a low-cost green antisolvent isopropanol (IPA) that displays ultrawide processing window, which dramatically enhances the reproducibility of PSCs. The highest power conversation efficiency of PSCs treated by IPA can reach as high as 24.8%. The origin of IPA effects is further disclosed by the intermolecular hydrogen-bonding force between IPA and DMF/DMSO, and the force can effectively remove DMF/DMSO in the spinning perovskite precursor film and helpfully enhance perovskite crystal growth with less carrier recombination as demonstrated by using various techniques. Our results here demonstrate a cheap green antisolvent for reproducible, high-efficient, stable PSCs and also provide an in-depth understanding the significant role of antisolvent in the fabrication of PSCs. [ABSTRACT FROM AUTHOR]

CsGeI2Br-based perovskites, with their favorable band gap and high absorption coefficient, are promising candidates for the development of efficient lead-free perovskite solar cells (PSCs). However, bulk and interfacial carrier non-radiative recombination losses hinder the further improvement of power conversion efficiency and stability in PSCs. To overcome this challenge, the photovoltaic potential of the device is unlocked by optimizing the optical and electronic parameters through rigorous numerical simulation, which include tuning perovskite thickness, bulk defect density, and series and shunt resistance. Additionally, to make the simulation data as realistic as possible, recombination processes, such as Auger recombination, must be considered. In this simulation, when the Auger capture coefficient is increased to 10−29 cm6 s−1, the efficiency drops from 31.62% (without taking Auger recombination into account) to 29.10%. Since Auger recombination is unavoidable in experiments, carrier losses due to Auger recombination should be included in the analysis of the efficiency limit to avoid significantly overestimating the simulated device performance. Therefore, this paper provides valuable insights for designing realistic and efficient lead-free PSCs. [ABSTRACT FROM AUTHOR]

SmNiO 3 is a representative quantum material exhibiting the antidoping behavior, where the conductivity of the material is reduced rather than increased by electron doping. Recent experimental and theoretical works have demonstrated a phase transition of SmNiO 3 with large conductance changes via chemical methods. However, the effect of electron doping via interfacial charge transfer in SmNiO 3 is much less studied. In this work, the first-principles density functional theory (DFT)+ U method is employed to investigate the SmNiO 3 /YTiO 3 superlattice, in which the YTiO 3 layer acts as the electron donor. Compared with the chemical doping in SmNiO 3 , several interesting physical phenomena have been predicted in SmNiO 3 /YTiO 3 superlattices due to the lattice and electronic reconstructions. First, at a doping concentration of 1 e − per Ni, i.e., (SmNiO 3) 1 /(YTiO 3) 1 superlattice, all Ni 3 + are converted to Ni 2 + , resulting in a Mott-insulating phase, similar to the chemical doping in the pristine material. Interestingly, such a Mott gap can be efficiently modulated by tuning the stacking orientation. Second, at a doping concentration of 1 2 e − per Ni, i.e., [ 001 ]-orientated (SmNiO 3) 2 /(YTiO 3) 1 superlattice, the electronic structure associated with charge ordering depends on the concrete magnetic order, giving rise to magnetism-dependent electronic behavior. In addition, as the doping concentration further decreases (i.e., a doping concentration of 1 3 e − /Ni), a metallic state is predicted in a [ 001 ]-orientated (SmNiO 3) 3 /(YTiO 3) 1 superlattice, which is quite different from the case of chemical doping. [ABSTRACT FROM AUTHOR]

Reducing kinetic energy barriers and developing accessible active sites are critical to deliver high hydrogen evolution reaction (HER) efficiency. In this paper, we synthesized defect-modulated and heteroatom (boron)-functionalized three-dimensional (3D) bowl-shaped Ti3-xC2Ty MXene (B-TCT) nanocavities coupled with the vertical growth of MoSe2 nanoflakes. The B-TCT@MoSe2 nanohybrids catalyst delivers the overpotentials of 49.9, 52.7, and 67.8 mV to reach a HER current density of 10 mA·cm-2 under acidic, alkaline, and neutral conditions, respectively. Such outstanding HER activity is predominantly attributed to the heteroatom functionalization, self-adapting Ti vacancy (VTi) defect modulation, and spatial configuration design in the 3D B-TCT nanocavity, which synergistically regulate the electronic structure, activate the basal plane/edge unsaturated sites, and reduce the reaction energy barrier. Experimental and theoretical calculations demonstrate that strong heterogeneous interfacial bonding interactions between B-TCT and MoSe2 can dramatically reduce the free energy of hydrogen adsorption and facilitate efficient interfacial charge migration, thus essentially improving the HER kinetics. We used this 3D porous nanohybrid system assembled by defect-rich lamellar structures to elucidate the advantageous synergistic effects of multiple mechanisms among defect structure, heteroatom functionalization, and interfacial coupling, which provided important insights for the development of efficient hybridtype catalysts. [ABSTRACT FROM AUTHOR]

In recent years, substantial progress has been made in improving the power conversion efficiency of perovskite solar cells (PSCs). However, persistent defects continue to impede their further advancement. Although ionic liquids (ILs) have been extensively utilized for perovskite defect passivation, their application, particularly in two-step methods, remains limited. In this study, we introduced formamidine acetate (FAAc) as a liquid additive, incorporated into the PbI2 precursor solution to finely regulate perovskite crystal growth. Utilizing a two-step method, we meticulously investigated the interaction of FAAc with perovskite components, laying the groundwork for effective defect passivation. Our systematic exploration delved into the nuanced influence of ILs on perovskite solar cells, including thin film morphology, optical properties, defect density, and overall device performance. Importantly, ILs facilitated the conversion of PbI2 into a perovskite material while reducing residual PbI2 during the perovskite crystallization process, thereby significantly improving the performance of PSCs, including device stability. Though defect passivation during perovskite formation facilitated the conversion of PbI2 and the modulation of thin film morphology, the photoelectric conversion efficiency of the treated PSCs approached an impressive 24.41%. Even after undergoing 2000 hours of aging in dry air, the efficiency remained at above 96% of the initial level. This research marks a pivotal step forward in the realm of PSCs. Our findings not only showcase the potential of ionic liquids in the two-step preparation of PSCs but also highlight their pivotal role in enhancing the efficiency and stability. [ABSTRACT FROM AUTHOR]