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Although three-dimensional metal halide perovskite (ABX3) single crystals are promising next-generation materials for radiation detection, state-of-the-art perovskite X-ray detectors include methylammonium as A-site cations, limiting the operational stability. Previous efforts to improve the stability using formamidinium–caesium-alloyed A-site cations usually sacrifice the detection performance because of high trap densities. Here we successfully solve this trade-off between stability and detection performance by synergistic composition engineering, where we include A-site alloys to decrease the trap density and B-site dopants to release the microstrain induced by A-site alloying. As such, we develop high-performance perovskite X-ray detectors with excellent stability. Our X-ray detectors exhibit high sensitivity of (2.6 ± 0.1) × 104 μC Gyair−1 cm−2 under 1 V cm−1 and ultralow limit of detection of 7.09 nGyair s−1. In addition, they feature long-term operational stability over half a year and impressive thermal stability up to 125 °C. We further demonstrate the promise of our perovskite X-ray detectors for low-bias portable applications with high-quality X-ray imaging and monitoring prototypes.X-ray detectors based on dual-site-doped perovskite single crystals exhibit excellent sensitivity of 2.6 × 104 μC Gyair−1 cm–2 under a low field of 1 V cm–1. The detectable dose rate is as low as 7.09 nGyair s–1. The operational stability is beyond half a year.

Excellent ductility is crucial not only for shaping but also for strengthening metals and alloys. The ever most widely used eutectic alloys are suffering from the limited ductility and losing competitiveness among advanced structural materials. Here we report a distinctive concept of phase-selective recrystallization to overcome this challenge for eutectic alloys by triggering the strain hardening capacity of the duplex phases completely. We manipulate the strain partitioning behavior of the two phases in a eutectic high-entropy alloy (EHEA) to obtain the phase-selectively recrystallized microstructure with a fully recrystallized soft phase embedded in the skeleton of a hard phase. The resulting microstructure fully releases the strain hardening capacity in EHEA by eliminating the weak boundaries. Our phase-selectively recrystallized EHEA achieves a high ductility of ∼35% uniform elongation with true stress of ∼2 GPa. This concept is universal for various duplex alloys with soft and hard phases and opens new frontiers for traditional eutectic alloys as high-strength metallic materials. The ever most widely used eutectic alloys often suffer from limited ductility. Here the authors propose a distinctive concept of phase-selective recrystallization to significantly improve their ductility and strength and pave the way for new applications of the widespread eutectic alloys.

Cations with suitable sizes to occupy an interstitial site of perovskite crystals have been widely used to inhibit ion migration and promote the performance and stability of perovskite optoelectronics. However, such interstitial doping inevitably leads to lattice microstrain that impairs the long-range ordering and stability of the crystals, causing a sacrificial trade-off. Here, we unravel the evident influence of the valence states of the interstitial cations on their efficacy to suppress the ion migration. Incorporation of a trivalent neodymium cation (Nd 3+ ) effectively mitigates the ion migration in the perovskite lattice with a reduced dosage (0.08%) compared to a widely used monovalent cation dopant (Na + , 0.45%). The photovoltaic performances and operational stability of the prototypical perovskite solar cells are enhanced with a trace amount of Nd 3+ doping while minimizing the sacrificial trade-off. Ion migration has a detrimental effect on the performance and stability of halide perovskite optoelectronics. Here, the authors incorporated a small dosage of high-valence neodymium cation to suppress this, with a minimal impact on the lattice microstrain.

Perovskite bandgap tuning without quality loss makes perovskites unique among solar absorbers, offering promising avenues for tandem solar cells 1 , 2 . However, minimizing the voltage loss when their bandgap is increased to above 1.90 eV for triple-junction tandem use is challenging 3 – 5 . Here we present a previously unknown pseudohalide, cyanate (OCN − ), with a comparable effective ionic radius (1.97 Å) to bromide (1.95 Å) as a bromide substitute. Electron microscopy and X-ray scattering confirm OCN incorporation into the perovskite lattice. This contributes to notable lattice distortion, ranging from 90.5° to 96.6°, a uniform iodide–bromide distribution and consistent microstrain. Owing to these effects, OCN-based perovskite exhibits enhanced defect formation energy and substantially decreased non-radiative recombination. We achieved an inverted perovskite (1.93 eV) single-junction device with an open-circuit voltage ( V OC ) of 1.422 V, a V OC  × FF (fill factor) product exceeding 80% of the Shockley–Queisser limit and stable performance under maximum power point tracking, culminating in a 27.62% efficiency (27.10% certified efficiency) perovskite–perovskite–silicon triple-junction solar cell with 1 cm 2 aperture area. Triple-junction solar cells with cyanate in ultrawide-bandgap perovskites exhibit enhanced defect formation energy and substantially decreased non-radiative recombination.

Photocatalytic formation of hydrocarbons using solar energy via artificial photosynthesis is a highly desirable renewable-energy source for replacing conventional fossil fuels. Using an l -cysteine-based hydrothermal process, here we synthesize a carbon-doped SnS 2 (SnS 2 -C) metal dichalcogenide nanostructure, which exhibits a highly active and selective photocatalytic conversion of CO 2 to hydrocarbons under visible-light. The interstitial carbon doping induced microstrain in the SnS 2 lattice, resulting in different photophysical properties as compared with undoped SnS 2 . This SnS 2 -C photocatalyst significantly enhances the CO 2 reduction activity under visible light, attaining a photochemical quantum efficiency of above 0.7%. The SnS 2 -C photocatalyst represents an important contribution towards high quantum efficiency artificial photosynthesis based on gas phase photocatalytic CO 2 reduction under visible light, where the in situ carbon-doped SnS 2 nanostructure improves the stability and the light harvesting and charge separation efficiency, and significantly enhances the photocatalytic activity. Photocatalytic reduction of CO 2 to hydrocarbons is a promising route to both CO 2 utilization and renewable fuel production. Here the authors identify that carbon-doped SnS 2 possesses a high catalytic efficiency towards CO 2 reduction owing to low photogenerated charge recombination rates.

Time resolved in situ (TRIS) monitoring has revolutionised the study of mechanochemical transformations but has been limited by available data quality. Here we report how a combination of miniaturised grinding jars together with innovations in X-ray powder diffraction data collection and state-of-the-art analysis strategies transform the power of TRIS synchrotron mechanochemical experiments. Accurate phase compositions, comparable to those obtained by ex situ measurements, can be obtained with small sample loadings. Moreover, microstructural parameters (crystal size and microstrain) can be also determined with high confidence. This strategy applies to all chemistries, is readily implemented, and yields high-quality diffraction data even using a low energy synchrotron source. This offers a direct avenue towards the mechanochemical investigation of reactions comprising scarce, expensive, or toxic compounds. Our strategy is applied to model systems, including inorganic, metal-organic, and organic mechanosyntheses, resolves previously misinterpreted mechanisms in mechanochemical syntheses, and promises broad, new directions for mechanochemical research. Time-resolved in situ (TRIS) X-ray powder diffraction promises great potential to study mechanochemical processes. Here, the authors develop a strategy to enhance the resolution of TRIS experiments to allow deeper interpretation of mechanochemical transformations; the method is applied to a variety of model systems including inorganic, metal-organic, and organic mechanosyntheses.

Hydroxyapatite (HA) from green mussel shells (Perna viridis) has been successfully synthesized with a variation of stirring time using the precipitation method. The green mussel shells were calcined in furnace at temperature of 950°C for 2 h. AAS result shows that the level of Ca was 49.5757%. X-Ray diffractometer result shows that the crystallization of CaO was high because it has big crystallite size and small microstrain. The analysis of XRD shows that for HA with the stirring time of 30 min and 45 min have the same crystallization with the crystallite size of (74.91 ± 4.9) nm and (74.91 ± 4.7) nm. From DTA/TGA analysis, HA samples of stirring time 45 min and 15 min are more stable than HA with the stirring time of 30 min. The FTIR spectra show that HA with the stirring time of 30 min and 45 min could have lower transmittance value. From SEM result, HA with the stirring time of 15 min has small agglomerate shape and thick structure of particles. Therefore, HA with the stirring time of 15 min becomes the best synthesized from this research which it can be used as a coating material in implanted applications.

All-perovskite tandem solar cells (APTSCs) offer the potential to surpass the Shockley-Queisser limit of single-junction solar cells at low cost. However, high-performance APTSCs contain unstable methylammonium (MA) cation in the tin-lead (Sn-Pb) narrow bandgap subcells. Currently, MA-free Sn-Pb perovskite solar cells (PSCs) show lower performance compared with their MA-containing counterparts. This is due to the high trap density associated with Sn 2+ oxidation, which is exacerbated by the rapid crystallization of MA-free Sn-containing perovskite. Here, a multifunctional additive rubidium acetate (RbAC) is proposed to passivate Sn-Pb perovskite. We find that RbAC can suppress Sn 2+ oxidation, alleviate microstrain, and improve the crystallinity of the MA-free Sn-Pb perovskite. Consequently, the resultant Sn-Pb PSCs achieve a power conversion efficiency (PCE) of 23.02%, with an open circuit voltage ( V oc) of 0.897 V, and a filling factor (FF) of 80.64%, and more importantly the stability of the device is significantly improved. When further integrated with a 1.79-electron volt MA-free wide-bandgap PSC, a 29.33% (certified 28.11%) efficient MA-free APTSCs with a high V oc of 2.22 volts is achieved. The high trap density associated with tin (II) oxidation impacts the device performance of methylammonium cation-free tin-lead perovskite solar cells. Here, authors employ rubidium acetate for defect passivation and achieve efficient and stable single-junction and all-perovskite tandem solar cells.

Microstrain and the associated surface-to-bulk propagation of structural defects are known to be major roadblocks to developing high-energy and long-life batteries. However, the origin and effects of microstrain during the synthesis of battery materials remain largely unknown. Here we perform microstrain screening during real-time and realistic synthesis of sodium layered oxide cathodes. Evidence gathered from multiscale in situ synchrotron X-ray diffraction and microscopy characterization collectively reveals that the spatial distribution of transition metals within individual precursor particles strongly governs the nanoscale phase transformation, local charge heterogeneity and accumulation of microstrain during synthesis. This unexpected dominance of transition metals results in a counterintuitive outward propagation of defect nucleation and growth. These insights direct a more rational synthesis route to reduce the microstrain and crystallographic defects within the bulk lattice, leading to significantly improved structural stability. The present work on microstrain screening represents a critical step towards synthesis-by-design of defect-less battery materials. In situ synchrotron X-ray tools are used to perform microstrain screening during solid-state synthesis of battery materials, leading to fewer structural defects and improved performance.

Highlights Crucial role of local microstrain was deciphered to boost oxygen electrocatalysis via quantitatively riveting asymmetric Fe–N 3 S 1 sites on carbon hollow nanospheres with specific curvature. The local microstrain accelerates kinetics of *OH reduction on Fe–N 3 S 1 , enabling much enhanced intrinsic activity, selectivity and stability toward oxygen electrocatalysis. The strained Fe–N 3 S 1 sites were monitored to transformed into Fe–N 3 –S 1 sites, further dynamically mitigating the overadsorption of *OH intermediates. Disrupting the symmetric electron distribution of porphyrin-like Fe single-atom catalysts has been considered as an effective way to harvest high intrinsic activity. Understanding the catalytic performance governed by geometric microstrains is highly desirable for further optimization of such efficient sites. Here, we decipher the crucial role of local microstrain in boosting intrinsic activity and durability of asymmetric Fe single-atom catalysts (Fe–N 3 S 1 ) by replacing one N atom with S atom. The high-curvature hollow carbon nanosphere substrate introduces 1.3% local compressive strain to Fe–N bonds and 1.5% tensile strain to Fe–S bonds, downshifting the d -band center and accelerating the kinetics of *OH reduction. Consequently, highly curved Fe–N 3 S 1 sites anchored on hollow carbon nanosphere (FeNS-HNS-20) exhibit negligible current loss, a high half-wave potential of 0.922 V vs. RHE and turnover frequency of 6.2 e −1  s −1 site −1 , which are 53 mV more positive and 1.7 times that of flat Fe–N–S counterpart, respectively. More importantly, multiple operando spectroscopies monitored the dynamic optimization of strained Fe–N 3 S 1 sites into Fe–N 3 sites, further mitigating the overadsorption of *OH intermediates. This work not only sheds new light on local microstrain-induced catalytic enhancement, but also provides a plausible direction for optimizing efficient asymmetric sites via geometric configurations.