Science Bulletin
·
2020
·
IF 9.511
Jianyong Feng,Xiaopeng Han,Huiting Huang,Qingxiao Meng,Zhi Zhu,Tao Yu,Zhaosheng Li,Zhigang Zou
Inorganic lead halide perovskite CsPbBr 3 offers attractive photophysical properties and phase stability for high-performance optoelectronic devices. However, CsPbBr 3 films produced by the classic solution-based two-step method are always accompanied with impurity phases of CsPb 2 Br 5 and Cs 4 PbBr 6 , which represents a major efficiency-limiting factor for future advances of CsPbBr 3 -based devices. The challenge lies in the complexity of the Cs-Pb-Br phase system, requiring both spatially and temporally precise control of the precursor stoichiometry during solution-phase growth of CsPbBr 3 films. By adopting 2-methoxyethanol as the solution conversion medium instead of commonly applied methanol, the reaction between CsBr and PbBr 2 can be finely controlled to yield single phase CsPbBr 3 films within a few minutes; extending the solution-conversion step to 24 h does not alter the phase purity of resulting CsPbBr 3 films. The present work paves the way to regulate the crystal growth behaviors of two-step solution-processed CsPbBr 3 films by simple solvent engineering.
研究领域:
材料科学
·
光电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Science Bulletin
·
2023
·
IF 18.9
Along Zhao,Fangjie Ji,Changyu Liu,Shihao Zhang,Kean Chen,Weihua Chen,Xiangming Feng,Faping Zhong,Xinping Ai,Hanxi Yang,Yongjin Fang,Yuliang Cao
Fe-based polyanionic sulfate materials are one of the most promising candidates for large-scale applications in sodium-ion batteries due to their low cost and excellent electrochemical performance. Although great achievements have been gained on a series of Na 6−2 x Fe x (SO 4 ) 3 (NFSO- x , 1.5 ≤ x ≤ 2.0) materials such as Na 2 Fe 2 (SO 4 ) 3 , Na 2 Fe 1.5 (SO 4 ) 3 , and Na 2.4 Fe 1.8 (SO 4 ) 3 for sodium storage, the phase and structure characteristics on these NFSO- x are still controversial, making it difficult to achieve phase-pure materials with optimal electrochemical properties. Herein, six NFSO- x samples with varied x are investigated via both experimental methods and density functional theory calculations to analyze the phase and structure properties. It reveals that a pure phase exists in the 1.6 ≤ x ≤ 1.7 region of the NFSO- x , and part of Na ions tend to occupy Fe sites to form more stable frameworks. The NFSO-1.7 exhibits the best electrochemical performance among the NFSO- x samples, delivering a high discharge capacity (104.5 mAh g −1 at 0.1 C, close to its theoretical capacity of 105 mAh g −1 ), excellent rate performance (81.5 mAh g −1 at 30 C), and remarkable cycle stability over 10,000 cycles with high-capacity retention of 72.4%. We believe that the results are useful to clarify the phase and structure characteristics of polyanionic materials to promote their application for large-scale energy storage.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
Materials Today Chemistry
·
2022
·
IF 7.613
S. Wu,Y. Fu,Q. Liu,P. Xiong,D. Wang,G. Zhang,S. Yuan,Y. Chen
Developing highly efficient cyan-emitting fluorescent materials is essential to bridge the cyan gap in phosphor-converted white light-emitting diodes for full-spectrum white illumination. Here, a Bi-doped cyan phosphor has been reported to solve this gap. The phase purity, photoluminescence emission/excitation spectra, concentration quenching, lifetime decay curves, and temperature-dependent photoluminescence emission spectra were systematically investigated. SrLaGaO 4 :Bi 3+ exhibits a broad excitation band (250–400 nm), which matches with the emission of a commercial near-ultraviolet light-emitting diode chip. The cyan light peaked at 475 nm is observed, which is attributed to the 3 P 1 → 1 S 0 transition of Bi 3+ . The thermal quenching experiment was performed, and the activation energy was calculated as 0.36 eV. Finally, full-spectrum white light-emitting diode devices were fabricated using SrLaGaO 4 :Bi 3+ phosphors, commercial blue BaMgAl 10 O 17 :Eu 2+ phosphor, green (Ba, Sr) 2 SiO 4 :Eu 2+ phosphor, and red CaAlSiN 3 :Eu 2+ phosphor, which displayed an International Commission on an illumination coordinate of (0.3732, 0.3850), a correlated color temperature of 4290 K, and a color rendering index of 93.2 at a drive current of 20 mA. This result indicates that SrLaGaO 4 :Bi 3+ plays an essential role in bridging the cyan gap, providing new inspiration for applying cyan-emitting phosphors in full-spectrum white lighting.
研究领域:
材料科学
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光学工程
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固态照明
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发光材料
·
无机化学
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2024
·
IF 1.8
Zhuo Xing,Julong Song,Hong Pan
The zinc orthosilicate, Zn 2 SiO 4 ceramics, exhibit great potential as microwave dielectric materials due to their low dielectric constant and ultrahigh quality factor. The solid-state synthesis of Zn 2 SiO 4 ceramics often results in the presence of a secondary phase of ZnO, however, leading to significantly lower Q × f values. Cold-isostatic-pressing (CIP) and nonstoichiometry have been proven effective in purifying the Zn 2 SiO 4 but need elaborate process and composition manipulation. In this work, it was found that the particle size of SiO 2 plays a crucial role in purifying the Zn 2 SiO 4 phase. Specially, nano-sized SiO 2 particles (15 and 30 nm) led to the formation of a ZnO secondary phase in synthesized Zn 2 SiO 4 ceramics, while micro-sized (2 and 10 µm) resulted in pure-phase Zn 2 SiO 4 with excellent microwave properties. Notably, when prepared with 10 µm SiO 2 and sintered at 1 340°C, the resulting Zn 2 SiO 4 exhibited outstanding microwave performances with a Q × f value of 122 570 GHz, a temperature coefficient of frequency τ f of −51.9 ppm/°C, and a dielectric constant ( ε r ) of 6.5. These findings highlight the importance of controlling particle size during synthesis to achieve desired material properties such as purity and excellent microwave performances.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2022
·Vol. 10
·期 23
·12632-12642
·
IF 14.511
Liang Shu,Xin Zhang,Wei Li,Jing Gao,Hongliang Wang,Yu Huang,Yue-Yu-Shan Cheng,Qian Li,Lisha Liu,Jing-Feng Li
AgNbO3-based antiferroelectric films have attracted emerging attention in the field of dielectric energy storage and possess promising applications in photocatalysis and microwave devices. Unfortunately, it remains a challenge to fabricate pure-phase AgNbO3 films on Si substrates, precluding their further integration into electronic devices. Here, we, for the first time, report phase-pure AgNbO3 films on Pt/Ti/SiO2/Si substrates by a chemical solution deposition (CSD) method. A facile CSD route without using the hazardous pyridine additive is demonstrated to obtain a stable AgNbO3 precursor for spin-coating films. By comprehensively controlling the heat treatment conditions, secondary phases are eliminated in the deposited films. The phase transitions of the AgNbO3 films are also investigated, where intriguingly the room temperature phase is determined to be the antiferroelectric M2 phase, rather than the commonly reported M1 phase in bulk AgNbO3. Meanwhile, the relative dielectric permittivity surpasses 300 at room temperature and maintains at ∼400 with low dielectric loss (<0.05; measured at frequencies of 0.1–1 MHz) over a wide temperature range of 150–350 °C, within a 5% variation. This work provides an easy-to-implement process of AgNbO3 films which may attract scientific interests and potential applications.
研究领域:
材料科学
·
电子工程
·
能源存储
✓ 已验证
DOI
高影响因子
International Journal of Applied Ceramic Technology
·
2023
·Vol. 20
·期 4
·2125-2130
·
IF 2.1
Jinghua Wu,Milad Kermani,Lei Cao,Bohan Wang,Zhiquan Dai,Le Fu,Chunfeng Hu,Salvatore Grasso
Lithium aluminum germanium phosphate solid electrolyte is a promising candidate for all-solid-state batteries. The currently available processing techniques based on melting-quenching require a rather lengthy crystallization step lasting up to 8 hours. In this work, the newly emerged ultra-fast high-temperature sintering (UHS) was proposed to achieve in a single step reactive consolidation of powder mixture (GeO 2 , Al(PO 3 ) 3 , LiPO 3 ) and crystallization of the electrolyte within 16 minutes. Samples produced using UHS had a better phase purity, reduced Li loss, and improved ionic conductivity when compared to the counterparts prepared using conventional crystallization at 850°C for 6 h. In fact, specimens prepared by UHS achieved a crystallinity of 90% and ionic conductivity as high as 1.31 × 10 −4 S cm −1 .
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Xingyue Liu,Xianhua Tan,Zhiyong Liu,Bo Sun,Junjie Li,Shuang Xi,Tielin Shi,Guanglan Liao
All-inorganic CsPbBr 3 perovskite has triggered great interests in photovoltaic field owing to its superior stability. However, the uncontrollable CsPbBr 3 film growth in solution always leads to a poor film quality with low phase-purity as well as many surface and bulk defects. Herein, we demonstrate an environmentally friendly non-solution route to fabricate high-quality CsPbBr 3 films for carbon-based planar perovskite solar cells . By precisely tuning the thickness ratio of the evaporated CsBr to PbBr 2 precursors ( r ), the dominant phase conversion of the cesium lead bromide perovskites from PbBr 2 -rich CsPb 2 Br 5 ( r ≤ 12:7) to CsPbBr 3 ( r = 12:8), and further to CsBr-rich Cs 4 PbBr 6 ( r ≥ 12:9) are achieved. The optimized CsPbBr 3 perovskites are highly phase-pure and crystallized with ultra-high light absorption ability. The as-prepared CsPbBr 3 films also exhibit a dense and uniform morphology with large grain sizes and monolayer-vertical aligned grains. The corresponding devices deliver a champion PCE of 7.58%, which is an excellent efficiency among carbon-based CsPbBr 3 cells with evaporated CsPbBr 3 light absorbers. The large-area (1 cm 2 ) devices also achieve an efficiency of 6.21%. Moreover, the unencapsulated CsPbBr 3 devices present superior moisture and thermal stabilities. Our work provides a facile approach to fabricate high-quality and large-area CsPbBr 3 films for highly efficient solar cells, light-emitting diodes and photodetectors .
研究领域:
材料科学
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能源科学
·
光伏技术
✓ 已验证
DOI
高影响因子
Journal of the American Chemical Society
·
2016
·
IF 13.038
Hai-Qun Xu,Kecheng Wang,Meili Ding,Dawei Feng,Hai-Long Jiang,Hong-Cai Zhou
The synthesis of phase-pure metal–organic frameworks (MOFs) is of prime importance but remains a significant challenge because of the flexible and diversified coordination modes between metal ions and organic linkers. In this work, we report the synthesis of phase-pure MOFs via a facile seed-mediated approach. For several “accompanying” pairs of Zr–porphyrinic MOFs that are prone to yield mixtures, by fixing all reaction parameters except introducing seed crystals, MOFs in phase-pure forms have been obtained because the stage of MOF nucleation, which generates mixed nuclei, is bypassed. In addition, phase-pure MOF isomers with distinct pore structures have also been prepared through such an approach, revealing its versatility. To the best of our knowledge, this is an initial report on seed-assisted synthesis of phase-pure MOFs.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Lei Gao,Yuanyuan Zhao,Yijie Chang,Kuidong Gao,Qiurui Wang,Qiang Zhang,Qunwei Tang
The presence of defects and residual tensile strain in perovskites has a significant and deleterious impact on the efficiency and stability of all-inorganic perovskite solar cells (PSCs). Here, dimethyl sulfoxide (DMSO) with strong polarity and high boiling point is introduced into the PbBr 2 precursor to delay the crystallization of PbBr 2 , leading to the formation of high-quality PbBr 2 films by delaying the solution reaching supersaturation. The formation of PbBr 2 (DMSO) adduct facilitates the complete reaction of PbBr 2 with CsBr via intramolecular exchange, thus preventing the formation of impurity phases such as CsPb 2 Br 5 . As a result, the defect density of CsPbBr 3 films decreased by 33% due to the improved phase purity, thicker films, larger grain sizes, and reduced grain boundaries. The small porosity of PbBr 2 film combined with a more complete phase-conversion process results in an expanded perovskite film that experiences compressive strain, effectively compensating for the tensile strain generated during annealing and thereby achieving the goal of strain relaxation. The optimized DMSO-based device, which exhibits compressive strain and minimal defects, achieves a remarkable efficiency of 10.11% with an open-circuit voltage of up to 1.611 V. Additionally, the unencapsulated PSC demonstrates excellent stability under 80% relative humidity and 80 °C over 30 days.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Li Song,Benzheng Zhou,Zhiyao Fu,Zhi Ye,Shaowei Ruan,Junjia He
Bi₂O₃ is a critical additive in ZnO varistor formulations and requires uniform distribution to optimize electrical performance. Surface coating technology enables the synthesis of ZnO@Bi₂O₃ core-shell particles, effectively mitigating the uneven distribution of Bi₂O₃ within the particles. Among the currently reported synthesis methods of ZnO@Bi₂O₃, there are significant variations in the selection of core material (ZnO source), and the coating effects obtained from different coating processes are highly inconsistent. Additionally, the characterization of coating structures remains scarce in the literature. This study proposes a novel synthesis route for ZnO@Bi₂O₃ particles, utilizing commercial nano-ZnO powder as the core material to ensure industrial quality standards for ZnO in production. Bismuth ions (Bi³⁺) are deposited via chemical precipitation to form the shell layer. Hydrothermal treatment strengthens the core-shell binding, facilitates phase transformation, and final calcination purifies the product to achieve the Bi₂O₃ phase. The effects of pH value and Bi³ ⁺/Zn²⁺ molar ratio were systematically investigated. Prepared ZnO@Bi₂O₃ core-shell structures were thoroughly characterized and analyzed using X-ray diffractometry (XRD), energy dispersive spectroscopy (EDS), and high-resolution transmission electron microscopy (HRTEM). The results indicate that the optimal coating performance is achieved when pH= 10.5 and the Bi³ ⁺/Zn²⁺ molar ratio is near 0.05, whereby the Bi₂O₃ phase forms uniform belt-like and spherical shells on the ZnO surface. This research integrates the common industry powder preparation techniques, including chemical precipitation, hydrothermal reaction, and calcination, to establish a foundational basis for the industrialization synthesis of ZnO@Bi₂O₃.
研究领域:
材料科学
·
纳米技术
·
无机非金属材料
·
电子陶瓷
·
功能材料
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry Letters
·
2022
·
IF 6.888
Xiao Zhao,Shimao Wang,Fuwei Zhuge,Yanan Song,Toru Aoki,Weiwei Dong,Mengyu Fu,Gang Meng,Zanhong Deng,Ruhua Tao,Xiaodong Fang
Considering the disadvantages of the common methods for CsPbBr3 single crystal growth including the high cost of the melt method and the low shape controllability of the solution method, a facile hot-pressed (HP) approach has been introduced to prepare CsPbBr3 wafers. The effects of HP temperature on the phase purity of HP-CsPbBr3 wafers and the performance of the corresponding photodetectors have been investigated. The HP temperature for preparing phase-pure, shape-regular, and dense CsPbBr3 wafers has been optimized to be 150 °C, and the HP-CsPbBr3 wafer based planar-type photodetectors exhibit an ultrasensitive weak light photoresponse. Under the illumination of a 530 nm LED with a light power density of 1.1 μW cm–2, the responsivity, external quantum efficiency, and detectivity of the devices reach 19.79 A W–1, 4634%, and 2.14 × 1013 Jones, respectively, and a fast response speed with a rise time of 40.5 μs and a fall time of 10.0 μs has been achieved.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
固体物理
✓ 已验证
DOI
高影响因子
Small
·
2024
·
IF 13
Yang Ding,Siyuan Lu,Jianhui Chang,Erming Feng,Hengyue Li,Caoyu Long,Yingguo Yang,Chenyi Yi,Zijian Zheng,Liming Ding,Junliang Yang
The crystallization process plays an important role in the formation of high-quality perovskite film for achieving efficient perovskite solar cells (PSCs), especially in the formation of mixed-cation perovskite film, as there are normally more phase impurities than in pure CH(NH 2 ) 2 PbI 3 (FAPbI 3 ) film. Herein, a molecular additive strategy, i.e., introducing non-planar molecule N-acetyl-L-phenylalanine (APO) into the lead iodide (PbI 2 ) precursor solution, is proposed to modulate crystallization kinetics and inhibit the generation of phase impurities of metastable pretreated perovskite film. The delayed crystallization process promotes a sufficient reaction between organic salts solution and inorganic Pb-I framework, and perovskite phase decomposition is prevented by forming strong hydrogen bonds between ─NH and I, resulting in the formation of uniform film with large-size crystal grains and high-purity crystalline phase. Ultimately, the target PSC devices achieve an impressive power conversion efficiency (PCE) of 25.05%, which is among the highest values of triple-cation (FAMACs) PSCs. Meanwhile, PSC modules with 10.8 cm 2 obtain a PCE of 20.35%. Furthermore, the unencapsulated PSCs retain 94% of the initial efficiency after 40 days of storage under ambient conditions with 20% RH and also yield superior operational stability under light soaking at maximum power point tracking (MPPT) in nitrogen (N 2 ) atmosphere.
研究领域:
材料科学
·
能源技术
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）