Materials
·
2019
·Vol. 12
·期 9
·1501
·
IF 2.972
Hongdan Zhang,Ludan Zhu,Jun Cheng,Long Chen,Chuanqi Liu,Shuanglong Yuan
In recent years, all-inorganic lead-halide perovskites have received extensive attention due to their many advantages, but their poor stability and high toxicity are two major problems. In this paper, a low toxicity and stable Cs2SnCl6double perovskite crystals were prepared by aqueous phase precipitation method using SnCl2as precursor. By the XRD, ICP-AES, XPS, photoluminescence and absorption spectra, the fluorescence decay curve, the structure and photoluminescence characteristics of Ce3+-doped and undoped samples have been investigated in detail. The results show that the photoluminescence originates from defects. [SnSn4+2++VCl] defect complex in the crystal is formed by Sn2+substituting Sn4+. The number of defects formed by Sn2+in the crystal decreases with Ce3+content increases. Within a certain number of defects, the crystal luminescence is enhanced with the number of [SnSn4+2++VCl] decreased. When Ce3+is incorporated into the crystals, the defects of [Ce3+Sn4++VCl] and [SnSn4+2++VCl] were formed and the crystal show the strongest emission. This provides a route to enhance the photoluminescence of Cs2SnCl6double perovskite crystals.Keywords:lead-free perovskite;Cs2SnCl6;doping;photoluminescence
研究领域:
材料科学
·
光电
·
固体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Baofei Sun,Wei Chen,Yanyi Huang,Daofu Wu,Heng Luo,Faguang Kuang,Hongmei Ran,Yichen Liu,Liqin Gao,Jinchen Zhou,Bo Gao,Qiang Huang,Xiaosheng Tang
Metal halide perovskites (MHP) are potential candidates for the photocatalytic reduction of CO 2 due to their long photogenerated carrier lifetime and charge diffusion length. However, the conventional long-chain ligand impedes the adsorption and activation of CO 2 molecules in practical applications. Here, a ligand modulation technology is employed to enhance the photocatalytic CO 2 reduction activity of lead-free Cs 2 AgInCl 6 microcrystals (MCs). The Cs 2 AgInCl 6 MCs passivated by Oleic acid (OLA) and Octanoic acid (OCA) are used for photocatalytic CO 2 reduction. The results show that the surface defects and electronic properties of Cs 2 AgInCl 6 MCs can be adjusted through ligand modulation. Compared with the OLA-Cs 2 AgInCl 6 , the OCA-Cs 2 AgInCl 6 catalyst demonstrated a significant improvement in the catalytic yield of CO and CH 4 . The CO and CH 4 catalytic yields of OCA-Cs 2 AgInCl 6 reached 171.88 and 34.15 µmol g −1 h −1 which were 2.03 and 12.98 times higher than those of OLA- Cs 2 AgInCl 6 , and the total electron consumption rate of OCA-Cs 2 AgInCl 6 was 615.2 µmol g −1 h −1 which was 3.25 times higher than that of OLA-Cs 2 AgInCl 6 . Furthermore, in situ diffuse reflectance infrared Fourier transform spectra revealed the enhancement of photocatalytic activity in Cs 2 AgInCl 6 MCs induced by ligand modulation. This study illustrates the potential of lead-free Cs 2 AgInCl 6 MCs for efficient photocatalytic CO 2 reduction and provides a ligand modulation strategy for the active promotion of MHP photocatalysts.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2019
·Vol. 9
·期 5
·258
·
IF 2.061
Hongdan Zhang,Ludan Zhu,Jun Cheng,Long Chen,Chuanqi Liu,Shuanglong Yuan
The Cs2SnX6perovskites have attracted much attention due to excellent optoelectronic properties and high stability. In the present work, we have focused on the morphology control and photoluminescence characteristics of the Cs2SnCl6perovskite crystals. The synthesis process of the Cs2SnCl6crystals includes two stages composed of the formation of initial crystals and the growth of Cs2SnCl6; the later originated from the oxidization of CsSnCl3. This process has been confirmed by Scanning electron microscope (SEM) and X-rays diffraction (XRD). By controlling the concentration of the initial reactants and hydrochloric acid in the solution to change the supersaturation of the solution, different crystal morphologies, such as truncated octahedron, octahedron, hexapod, quasi-sphere, have been obtained. In relatively a low supersaturation solution, the amount of growth units dominates the crystal growth process to obtain the hexapod and self-assembly crystals. In contrast, in relatively high supersaturation solution, nucleation predominates to yield small size truncated octahedrons and near-spherical Cs2SnCl6crystals. The synthesized Cs2SnCl6crystals have shown a wide emission band peaking at 450 nm with full width at half maximum (FWHM) 63 nm due to the defects introduced by Sn2+. The photoluminescence intensities of crystals synthesized at various conditions exhibited considerable difference, which was about 60 times between the highest and the lowest.Keywords:lead-free perovskite;Cs2SnCl6;crystal growth;photoluminescence
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materiomics
·
2024
·
IF 8.4
Yingzhi Meng,Silin Tang,Zhaojie Wang,Xiang Niu,Hongfang Zhang,Dingyuan Wang,Yisong Bai,Biaolin Peng,Sheng-Guo Lu,Qingqing Ke,Laijun Liu
The electrocaloric effect (ECE) offers a pathway to environmentally sustainable and easily miniaturized refrigeration technology, positioning it as a front-runner for the next generation of solid-state cooling solutions. This research unveils a remarkable ECE in a finely tuned (Ba 0.86 Ca 0.14 ) 0.98 La 0.02 Ti 0.92 Sn 0.08 O 3 ceramic, exhibiting a temperature shift (Δ T ) of 1.6 K across more than 85% of the maximum Δ T (Δ T max ) and spanning an exceptionally wide operational range of 92 K. Our investigation on dielectric responses and ferroelectric polarization-electric field ( P–E ) loops suggests that the broad operational scope results from the fragmentation of extended ferroelectric domains into smaller domains and polar nano-regions (PNRs) supported by PFM analysis. Furthermore, the introduction of La enhances spontaneous polarization by significantly extending the maximum electric field that can be applied, facilitating high-performance ECE at ambient temperature. This study positions BaTiO 3 -based lead-free ceramic as a sustainable alternative for addressing the cooling demands of modern electronic components, marking a significant stride toward next-generation solid-state refrigeration.
研究领域:
材料科学
·
固态制冷技术
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Jiajun Ma,Donghai Zhang,Fei Ying,Xiongjie Li,Ling Li,Shun Guo,Yu Huan,Ji Zhang,Jing Wang,Shan-Tao Zhang
Dielectric capacitors have attracted growing attention because of their important applications in advanced high power and/or pulsed power electronic devices. Nevertheless, the synergistic enhancement of recoverable energy storage density (Wrec > 10 J/cm3) and efficiency (η > 80%) is still a great challenge for lead-free dielectric bulk ceramics. Herein, by introducing complex perovskite compound (Bi0.9Na0.1)(Fe0.8Ti0.2)O3 with a smaller tolerance factor into an NaNbO3 matrix (NN-BNFT), we have achieved and explored stable relaxor antiferroelectric ceramics with enhanced relaxor behavior. Of particular importance is the composition of 0.88NN-0.12BNFT, which exhibits a large electric breakdown strength Eb of 87.3 kV/mm, an ultrahigh Wrec of 12.7 J/cm3, and a high efficiency η of 82.5%, as well as excellent thermal reliability and an ultrafast discharge speed, resulting from the dense microstructure, the moderate dielectric constant, the reduced grain size, the dielectric loss, and the sample thickness. The outstanding energy storage properties of NN-BNFT display great promise in advanced dielectric capacitors for energy storage applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2022
·Vol. 27
·期 23
·8259
·
IF 4.927
Ping Gao,Suwen Cheng,Jiaxin Liu,Junjie Li,Yanyan Guo,Zhengtao Deng,Tianshi Qin,Aifei Wang
Lead-free all-inorganic halide materials with different Mn2+-based crystal structures (Cs3MnBr5and CsMnBr3) were obtained using a convenient synthetic method. Cs3MnBr5had a bright green emission (522 nm), with a unique single-exponential lifetime (τavg= 236 µs) and a high photoluminescence quantum yield (82 ± 5%). A red emission was observed in the case of the CsMnBr3structure with a two-exponential fluorescence decay curve, and the lifetime was 1.418 µs (93%) and 18.328 µs (7%), respectively. By a judicious tuning of the synthetic conditions, a mixed phase of Cs3MnBr5/CsMnBr3was also produced that emitted white light, covering almost the entire visible spectrum. White-light-emitting diodes (WLEDs) with color coordinates (0.4269, 0.4955), a color temperature of (3773 K), and a color rendering index (68) were then fabricated using the as-prepared powder of mixed phases of Cs3MnBr5/CsMnBr3with a commercial UV LED chip (365 nm).Keywords:perovskite;Cs3MnBr5;manganese halide;phosphor;white LEDs
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 7
·9032-9043
·
IF 2.478
Liu Yunyi,Pan Yongqi,Bai Xudong,Wang Jinchuan,He Caiwang,Xu Zunping,Chen Yi
A conventional ceramic preparation method was used to fabricate the newly designed ternary (K,Na)NbO 3 -based lead-free ceramics, which have the general formula of (0.97- x )K 0.40 Na 0.60 Nb 0.95 Sb 0.05 O 3 –0.03Bi 0.5 K 0.5 HfO 3 – x SrZrO 3 . An X-ray diffraction analysis, together with dielectric-temperature measurements, was performed for determining their phase structures. The crystal structure was found to transition from a rhombohedral-orthogonal phase coexistence to a three-phase coexistence of rhombohedral-orthogonal-tetragonal phases with the increase in SrZrO 3 concentration, and then to a rhombohedral-tetragonal phase coexistence, and finally to a single rhombohedral phase. Near the three-phase coexistence zone, the ceramics exhibit an obviously enhanced electrical activity, with an electromechanical coupling coefficient k p = 0.364 and a piezoelectric constant d 33 = 280 pC/N. Through a microstructure analysis, a slightly excessive amount of SrZrO 3 was found to result in an inhibition for the grain growth of the studied ceramics. These results show that incorporating SrZrO 3 into ternary (K,Na)NbO 3 -based ceramics is still an effective means of constructing phase boundaries and improving the electromechanical properties.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Chuangchuang Wei,Jihui Wang,Lijin Wang,Jinxing Zhao,Zhe Yin,Aiwei Tang
Perovskites have made remarkable advancements in optoelectronics owing to their high light absorption coefficient, tunable bandgap, and long charge diffusion. Nonetheless, the practical applications of Pb-based perovskites have been hindered by the instability and toxicity of Pb, especially in flexible electronics, which require high biosecurity and low toxicity. Hence, the development of stable Pb-free perovskite materials has gained increasing attention. In this study, we synthesized stable CsBi3I10 Pb-free perovskites outside the glovebox and improved the optoelectronic and mechanical performances of the CsBi3I10-based flexible devices through polyvinylcarbazole (PVK) doping. Flexible photodetectors with the device structure of PET/ITO/PEDOT:PSS/CsBi3I10:PVK/Au was fabricated. The results indicated that the introduction of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) reduced the surface roughness of the flexible PET substrate, while PVK doping further improved the surface smoothness of CsBi3I10 thin films, thereby enhancing the interfacial charge transportation. Moreover, PEDOT:PSS and PVK acted as stepwise hole transport layers in the photodetectors. The device demonstrated a maximum responsivity of 0.3 A/W, detectivity of 2.6 × 1011 Jones, and a response time of 102 μs at 650 nm. After subjecting it to 1000 bending tests, the light current retained 80% of its initial value. This study presents a universally applicable method for controlling the surface morphology of a flexible perovskite thin film.
研究领域:
材料科学
·
光电材料
·
柔性电子
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY-A EUROPEAN JOURNAL
·
2024
·
IF 3.9
Minjie Wu,Teng Chen,Xuedan Chen,Maoxue Wang,Chen Lv,Kai Meng,shuanglong Yuan
Perovskite-based photodetectors (PDs) are broadly utilized in optical communication, non-destructive testing, and smart wearable devices due to their ability to convert light into electrical signals. However, toxicity and instability hold back their mass production and commercialization. The lead-free Cs2AgBiBr6 double perovskite film, promised to be an alternative, is fabricated by electrophoretic deposition (EPD), which compromises film quality. Herein, we improved the quality of the Cs2AgBiBr6 films and the performance of PDs by adding N-acetylethylenediamine (DEAC) to Cs2AgBiBr6 perovskite precursor for EPD, in which the ligand DEAC provides a pair of lone electrons to Bi3+, forming coordinate covalent bonds. The optimized PDs have high detectivity, up to 4.4×1012 Jones, and high stability in the air. The high-performance, flexible Cs2AgBiBr6 perovskite PDs were fabricated on this basis, it also achieved the detectivity up to 3.2×1012 Jones with excellent bending cycle stability. These results propose a feasible approach to improving the crystallization of double perovskite thin films by introducing ligands during the EPD process. Furthermore, they demonstrate enhanced optoelectronic performance, indicating that this method is also applicable to halide perovskites, offering an effective strategy to improve their film quality.
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Science and Engineering B-Advanced Functional Solid-State Materials
·
2024
·
IF 3.9
Xianzhao Zhang,Qiyi Yin,Hengwen Cheng,Ruihua Zheng,Hui Zhang,Kunhong Hu,Fei Lin,Liping Fang,Shicheng Wang,Zhen Zhang
In this study, new lead-free piezoelectric ceramics (1 − x )(K 0.5 Na 0.5 )NbO 3 (KNN)– x (Bi 0.45 Y 0.05 )Na 0.5 ZrO 3 (BYNZ) were prepared using the conventional solid-state method, and the relation between the doping amount of (Bi 0.45 Y 0.05 )Na 0.5 ZrO 3 and its structural and electrical properties was investigated. Material characterization and structural analyses conducted using X-ray diffraction, scanning electron microscopy, and energy-dispersive spectroscopy revealed that KNN–BYNZ ceramics formed single perovskite structures at 0 ≤ x ≤ 0.05 and a polycrystalline phase boundary (PPB) for the coexisting orthorhombic and tetragonal phases at 0.03 ≤ x ≤ 0.05. The ceramics exhibited desirable electrical properties at x = 0.04 ( d 33 = 305 pC/N, k p = 45.8 %, ε r = 1316, tanδ = 2.4 %, T c = 332 °C, P r = 28.2 μC/cm 2 , and E c = 1.07 kV/mm). These findings reveal that the introduction of BYNZ enables the effective formation of a PPB in the KNN-based ceramics to improve their electrical properties, and they exhibit potential for replacing lead-based piezoelectric ceramics in the market.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Materials Today Chemistry
·
2021
·
IF 8.301
Xiaoyong Huang,Shaoying Wang,Balaji Devakumar,Nan Ma
The development of new efficient and environmental-friendly inorganic phosphors is highly important for phosphor-converted white light-emitting diodes and optoelectronic displays. In this paper, we report a novel and simple one-step solid-state reaction to synthesize lead-free cesium copper halide Cs 3 Cu 2 Br 5 powders with bright blue emission around 460 nm. The preparation process is performed at low calcination temperatures (290–320 °C) and requires no complex apparatus, reagents, or techniques, and thus it holds great potential for mass production of halide emitters. The Cs 3 Cu 2 Br 5 powder phosphors are characterized by X-ray diffraction, field-emission scanning electron microscopy, energy dispersive X-ray spectroscopy, photoluminescence excitation and emission spectroscopy , CIE color coordinates, color purity, photoluminescence quantum yield, and temperature-dependent emission spectra . The effect of calcination temperature on the photoluminescence properties of the as-prepared Cs 3 Cu 2 Br 5 blue phosphors has been investigated and the air-stability property has also been discussed. Impressively, Cs 3 Cu 2 Br 5 blue phosphors show outstanding stability toward air exposure exceeding one month (30 days). Our work will open a new and simple approach to obtain excellent halide emitters for future solid-state lighting and displays.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Huajun Sun,Saihong Duan,Xiaofang Liu,Dawei Wang,Huiting Sui
Lead-free Ba 0.98 Ca 0.02 Zr 0.02 Ti 0.98 O 3 -xmol% MnO 2 (BCZT-xMn) (x = 0.1, 0.2, 0.3, 0.4, 0.5) ceramics were prepared by conventional solid-state reaction method and the effects of MnO 2 doping content and sintering temperature on microstructure and electrical properties of BCZT ceramics were studied. The ceramics samples with all MnO 2 doping contents exhibit pure perovskite structure and similar Curie temperature of approximately 120 °C. Among all, the sample with 0.3 mol. % MnO 2 doping content sintered at 1400 °C exhibits improved ferroelectricity with a relatively high remnant polarization ( P r ) and low coercive electric field ( E c ) of 15.7 μC/cm 2 and 180 V/mm, respectively, which can be attributed to the fact that an appropriate doping content of MnO 2 does favor to the grain growth, with the favorable effect on domain motion. Accordingly, excellent piezoelectric property with piezoelectric coefficient ( d 33 ) of 308 pC/N can be obtained. Besides, the sample shows a relatively low dielectric loss (tanδ) of 1.04%. As a result, the BCZT-xMn ceramic exhibits the potential to be used in memory and transformer applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）