PHYSICA B-CONDENSED MATTER
·
2022
·
IF 2.988
Xianzhi Zeng,Haoyi Wu,Junhao Peng,Chuanlong Wang,Guangting Xiong,Yahong Jin,Yihua Hu
The improvement of luminescent properties is important for expanding the application of long afterglow phosphor (LAP). Here, the melilite-type Sr 1·97 MgSi 2 O 7 : Eu 2+ 0.01 , Dy 3+ 0.02 LAP was studied with Bi 3+ as the second co-dopant. Both photoluminescence (PL) and thermoluminescence (TL) were improved in terms of intensity and afterglow lifetime when the doping concentration of Bi 3+ exceeded 2.5 mol%, and the optimized point was 3.5 mol%. As compared to the case of Eu 2+ - Dy 3+ double doping, the improved PL of Eu 2+ - Dy 3+ - Bi 3+ triple doping samples was attributed to better photon absorption . The improved TL and afterglow were attributed to the synergistic strengthening density of the traps by Bi 3+ and the deepening of trapping by Dy 3+ , if their distance was sufficient close. As a result, both TL and afterglow optimized at a concentration of 2 mol% Dy 3+ - 3.5 mol% Bi 3+ coupling.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2023
·
IF 6.4
Ronghuan Liu,Bihua Hu,Kai Wang,Baomin Xu,Xiao Wei Sun
Compared with polycrystalline thin films, perovskite single crystals without grain boundaries have better photovoltaic performance and stability. However, due to the extremely low solubility of all-inorganic perovskite in organic solvents and the complex phase diagram of CsPbBr3, directly growing large-sized CsPbBr3 perovskite single-crystal wires is challenging. Here, we have developed an airflow-assisted growth method for the rapid synthesis of large quantities of high-quality, dispersed, ultralong CsPbBr3 single-crystal wires under ambient conditions. This method is green (no additives) and low cost (no special treatment). The growth kinetics of single-crystal wires using this method have been elucidated, and their structural and optoelectronic properties were characterized. Some of the CsPbBr3 single-crystal wires synthesized by this method can exceed 1 mm in length with a low trap density of about 9.06 × 1011 cm–3. The constructed photodetector responsivity is up to 0.365 A/W and detectivity is over 3.3 × 1013 Jones, indicating great potential for optoelectronic applications. This low-cost, high-quality all-inorganic CsPbBr3 single-crystal wire growth method is highly scalable and may facilitate the research and application of all-inorganic perovskite single crystals.
研究领域:
材料科学
·
光电化学
✓ 已验证
产品关联
DOI
高影响因子
ACTA MATERIALIA
·
2018
·
IF 6.036
Jun-Cheng Zhang,Xin-Hua Fan,Xu Yan,Feng Xia,Weijin Kong,Yun-Ze Long,Xusheng Wang
Trap-controlled mechanoluminescence (ML) enables the direct observation of stress concentration of load-bearing objects through imaging the ML distribution, showing numerous prospects in stress detection, bio-imaging and optical displays. However, the applications of trap-controlled ML materials universally require long-time delay to fade the noise of symbiotic persistent luminescence (PersL) in order to achieve high-contrast ML images. In view of the difficulty to solve the PersL problem through individually eliminating the PersL traps, herein we propose a novel strategy of sacrificing trap density which decreases PersL and ML traps as a whole. By employing Sr 2+ substitution to decrease the trap density of Ca 2 Nb 2 O 7 :Pr 3+ , we identify a novel composition of (Ca 0.5 Sr 0.5 ) 2 Nb 2 O 7 :Pr 3+ displaying short-delay and high-contrast ML images, and evaluate its practicability through a 2-dimensional in-situ imaging experiment of dynamic stress distribution. The underlying mechanism is ascribed to the greater decrease ratio of PersL intensity than ML intensity as a result of the larger detrapping rate of traps due to stress (leading to ML) than that due to thermal energy (PersL). Furthermore, multi-spectral investigations of (Ca,Sr) 2 Nb 2 O 7 :Pr 3+ system reveal a distinctive electron transition process co-regulated by trap levels, charge transfer state and crystal field . The proposed strategy and the associated phosphors are expected to initiate the reconstruction of PersL-type ML materials and bring important implications for real-world stress imaging.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Joule
·
2024
·
IF 38.6
Wenbo Lu,Mingjie Feng,Zongbao Li,Bin Yan,Shuo Wang,Xin Wen,Xiaoyan An,Shunchang Liu,Jin-Song Hu,Ding-Jiang Xue
As the world’s first solid-state solar cells, selenium (Se) cells initiated contemporary photovoltaic research. However, the highest efficiency of Se photovoltaics has stagnated at 6.5% since 2017. Here, we report Se solar cells with a certified record efficiency of 7.2% through a critical melting-annealing strategy. This strategy provides enough energy to overcome the high activation energy of disordered Se chains and incorporate them into the lattice, arising from the unique one-dimensional crystal structure of photoactive trigonal Se. The resulting Se films exhibit a 2.3-fold reduction in trap density compared with conventional Se films. Such high-performance Se cells also achieve an efficiency of 18.0% under 1,000-lux indoor illumination, owing to their suitable wide band gap (∼1.9 eV) for indoor photovoltaics (IPVs). This efficiency surpasses those of market-dominant amorphous silicon and all currently available lead-free perovskite IPVs. We further construct Se IPV modules capable of generating a power of 559.8 μW, achieving self-powered wireless electronic shelf labels.
研究领域:
材料科学
·
光伏技术
·
能源转换
✓ 已验证
产品关联
DOI
高影响因子
Science China-Materials
·
2025
·
IF 7.4
Chen Wenliang,Zhang Yingze,Zhu Xiaoyu,Miao Junhui,Liu Jun,Wang Lixiang
Near-infrared (NIR) organic photodetectors (OPDs) hold enormous commercial potential in wearable biosensing and imaging applications. However, their sensitivity remains comparatively lower than that of commercially available silicon-based photodetectors (Si PDs). In this study, we present highly sensitive NIR OPDs by incorporating an all-fused-ring small molecule acceptor, FM4, with low trap density into a conventional active layer system. FM4 effectively reduces traps in the active layer, resulting in a decrease in trap density from 1.57 × 10 15 to 8.86 × 10 14 cm −3 . Consequently, under −1 V bias, the OPD device with FM4 as the third component achieves an ultra-low real-measured noise current of 7.56 × 10 −15 A Hz −1/2 at 1 kHz, lower than that of commercial Si PDs, which is primarily attributed to the substantial decrease in trap density within the active layer. Due to its ultra-low noise current, the ternary device exhibits a high specific detectivity of 1.83 × 10 13 Jones at 840 nm under −1 V bias and a broad linear dynamic range of 155 dB. Its sensitivity exceeds that of Si PDs. Furthermore, this sensitive OPD device has been successfully utilized in single-pixel low-light imaging, delivering superior image clarity compared to Si PDs.
研究领域:
材料科学
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光学工程
·
生物医学工程
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产品关联
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2023
·Vol. 129
·期 11
·1-7
·
IF 2.7
Yin Qianliu,Zhang Fanfan,Teng Yanlin,Peng Cong,Wang Chaonan,Jin Yonglong,Xu Meifeng,Xu Tian
Different concentrations of NH 4 Cl are introduced to MAPbI 3 precursor solution, planar MAPbI 3 perovskite films, and solar cells’ performance with or without NH 4 Cl have been studied. The NH 4 Cl/MAPbI 3 films exhibit increased grain size and narrowed grain boundaries. The light absorption of perovskite films with different concentrations of NH 4 Cl was also evaluated. To understand the growth of perovskite films with NH 4 Cl added to perovskite precursor solutions, XRD and XPS spectroscopy were conducted on different perovskite film samples. By adding NH 4 Cl, the MAPbI 3 film shows good crystal quality and the shift of Pb peaks indicates that NH 4 Cl is not physically mixed but chemically incorporated into MAPbI 3 films. We attribute the effect to Cl ions of NH 4 Cl combining with free lead ions of MAPbI 3 so as to fill the vacancy of volatile I ions in the NH 4 Cl–MAPbI 3 films. The 20 mg NH 4 Cl-based device showed an enhanced performance of a PCE of 13.67% compared to the device without adding NH 4 Cl with a PCE of 10.24%. The introduction of 20 mg NH 4 Cl achieved the best passivation effect. Using a 20 mg NH 4 Cl device, the trap density can be reduced to 0.84 × 10 16 cm −3 , resulting in more efficient charge removal from the surface and improved performance.
研究领域:
材料科学
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太阳能
·
化学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2019
·Vol. 21
·期 6
·3106-3113
·
IF 3.567
Guangbao Wu,Jiyu Zhou,Rui Meng,Baoda Xue,Huiqiong Zhou,Zhiyong Tang,Yuan Zhang
Here based on integral microcrystal (IMC) thin films of halide perovskites containing formamidinium (FA)/methylammonium (MA) mixed cations, afforded by a facile approach combining an anti-solvent and inverse temperature crystallization, we investigate the impact of the addition of MAPbBr3 on the phase, thermal and environmental stabilities as well as the opto-electronic properties in FA-based IMC films. By single-crystal XRD, FA based IMCs have been found to possess a perfect cubic structure showing a slight lattice contraction compared to pristine FAPbI3 crystals. In conjunction with optical and electrical analyses, the essential role of the introduced MA and Br ions in stabilizing the black phase in FA-based IMCs has been clarified, which explains the observed enhancement of photoluminescence and reduced trap densities. We also achieve stable pure FAPbI3 crystals that do not exhibit a yellow-phase transition after one month in air. By utilizing (FAPbI3)1−x(MAPbBr3)x IMCs as the photo-absorber, we realize highly photo-responsive photodiodes with a satisfactory stability in air and thermal stability upon heating. Of interest, the best photoresponsivity exceeding 300 A W−1 is achieved upon appropriate air-exposure, which is among the highest values reported for FA-based perovskite photodetectors. The air-modified optoelectronic behaviour can be related to the trap passivation through the surface physisorption of the environmental O2, leading to reduced trap densities and resultant harmful SRH recombination.
研究领域:
材料科学
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光电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Wei Gong,Peng Wang,Wenjie Deng,Xiaobo Zhang,Boxing An,Jingjie Li,Zhaoqing Sun,Dichao Dai,Zekang Liu,Jingzhen Li,Yongzhe Zhang
Lead sulfide colloidal quantum dots (PbS CQDs) have shown great potential in photodetectors owing to their promising optical properties, especially their strong and tunable absorption. However, the limitation of the specific detectivity (D*) in CQD near-infrared (NIR) photodetectors remains unknown due to the ambiguous noise analysis. Therefore, a clear understanding of the noise current is critically demanded. Here, we elucidate that the noise current is the predominant factor limiting D*, and the noise is highly dependent on the trap densities in halide-passivated PbS films and the carriers injected from the Schottky contact (EDT-passivated PbS films/metal). It is found that the thickness of CQDs is proportional to their interface trap density, while it is inversely proportional to their minimal bulk trap density. A balance point can be reached at a certain thickness (136 nm) to minimize the trap density, giving rise to the improvement of D*. Utilizing thicker PbS-EDT films broadens the width of the tunneling barrier and thereby reduces the carrier injection, contributing to a further enhancement of D*. The limiting factors of D* determined in this work not only explain the physical mechanism of the influence on detection sensitivity but also give guidance to the design of high-performance CQD photodetectors.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
PubMed
高影响因子
IEEE TRANSACTIONS ON DIELECTRICS AND ELECTRICAL INSULATION
·
2024
·
IF 2.9
Yifan Wu,Shihang Wang,Bingrong Huang,Xinru Yang,Shengtao Li
The byproducts of crosslinked polyethylene (XLPE) for high-voltage cables reduce the purity of the insulation, thereby limiting its DC electrical performance. The byproduct-free click chemistry reaction between polyethylene copolymers demonstrates significant potential as an alternative to peroxide crosslinking. In this paper, polyethylene copolymer blends were prepared, and their thermal properties, chemical composition, crystalline structure and dielectric characteristics were evaluated comprehensively. A low-density polyethylene and the resulting XLPE for high voltage cables were selected as references. In addition, the effect of antioxidant on the structure and properties of polyethylene copolymer blends was explored. The results show that the polyethylene copolymer blends exhibit superior DC electrical performance owing to the higher density of deep traps. The incorporation of polar groups in the copolymer blends affects the development of crystallization, resulting in reduced crystallinity and diminished spherulite size. More importantly, the polar groups in the copolymer blends significantly increase the density of deep traps which suppress the space charge injection and enhance the DC breakdown strength. These findings suggest that this novel insulating material holds promising prospects in the field of DC cable insulation.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Research
·
2022
·
IF 11.036
Jiayu Di,Haojin Li,Li Chen,Siyu Zhang,Yinhui Hu,Kai Sun,Bo Peng,Jie Su,Xue Zhao,Yuqi Fan,Zhenhua Lin,Yue Hao,Peng Gao,Kui Zhao,Jingjing Chang
Exploring halogen engineering is of great significance for reducing the density of defect states in crystals of organic-inorganic hybrid perovskites and hence improving the crystal quality. Herein, high-quality single crystals of PEA2PbX4 (X = Cl, Br, I) and their para-F (p-F) substitution analogs are prepared using the facile solution method to study the effects of both p-F substitution and halogen anion engineering. After p-F substitution, the triclinic PEA2PbX4 (X = Cl, Br) and cubic PEA2PbX4 (X = I) crystals unifies to monoclinic crystal structure for p-F-PEA2PbX4 (X = Cl, Br, I) crystals. The p-F substitution and halogen engineering, together with crystal structure variation, enable the tunability of optoelectrical properties. Experimentally, after the p-F substitution, the energy levels are lowered with increased Fermi levels, and the bandgaps of p-F-PEA2PbX4 (X = Cl, Br, I) are slightly reduced. Benefitting from the enhancement of the charge transfer and the reduced trap density by p-F substitution and halogen anion engineering, the average carrier lifetime of the p-F-PEA2PbX4 is obviously reduced. Compared with PEA2PbI4, the X-ray detector based on p-F-PEA2PbI4 perovskite single-crystal has a higher sensitivity of 119.79 μC Gyair-1·cm-2. Moreover, the X-ray detector based on p-F-PEA2PbI4 single crystals exhibits higher radiation stability under high-dose X-ray irradiation, implying long-term operando stability.
研究领域:
材料科学
·
光电材料
·
辐射探测
✓ 已验证
DOI
高影响因子
ADVANCED MATERIALS
·
2023
·Vol. 35
·期 29
·2301406
·
IF 29.4
Haodi Wu,Xu Chen,Zihao Song,Ao Zhang,Xinyuan Du,Xin He,Hanqi Wang,Ling Xu,Zhiping Zheng,Guangda Niu,Jiang Tang
Perovskites are attracting attention for optoelectronic devices. Despite their promise, the large-scale synthesis of perovskite materials with exact stoichiometry, especially high-entropy perovskites, has been a major challenge. Moreover, the difficulty in stoichiometry control also hinders the development of perovskite X-ray flat-panel detectors. Previous reports all employed simple MAPbI 3 as the active layer, while the performance still falls short of optimized single-crystal-based single-pixel detectors. Herein, a scalable and universal strategy of a mechanochemical method is adopted to synthesize stoichiometric high-entropy perovskite powders with high quality and high quantity (>1 kg per batch). By utilizing these stoichiometric perovskites, the first FA 0.9 MA 0.05 Cs 0.05 Pb(I 0.9 Br 0.1 ) 3 -based X-ray flat-panel detector with low trap density and large mobility–lifetime product (7.5 × 10 −3 cm 2 V −1 ) is reported. The assembled panel detector exhibits close-to-single-crystal performance (high sensitivity of 2.1 × 10 4 µC Gy air −1 cm −2 and ultralow detection limit of 1.25 nGy air s −1 ), high spatial resolution of 0.46 lp/pixel, as well as excellent thermal robustness under industrial standards. The high performance in the high-entropy perovskite-based X-ray FPDs has the potential to facilitate the development of new-generation X-ray-detection systems.
研究领域:
材料科学
·
医学成像
·
光学电子器件
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Small Methods
·
2024
·
IF 10.7
Kaixin Liu,Fengyuan Zhang,Zhigang Liu,Chunlin Song,Lingyu Zhang,Wenjie Ming,Lingyu Yang,Yao Wang,Boyuan Huang,Jiangyu Li
Nanocomposites combining inorganic nanoparticles with high dielectric constant and polymers with high breakdown strength are promising for the high energy density storage of electricity, and carrier traps can significantly affect the dielectric breakdown process. Nevertheless, there still lacks direct experimental evidence on how nanoparticles affect the trap characteristics of nanocomposites, especially in a spatially resolved manner. Here, a technique is developed to image the trap distribution based on sequential Kelvin probe force microscopy (KPFM) in combination with the isothermal surface potential decay (ISPD) technique, wherein both shallow and deep trap densities and the corresponding energy levels can be mapped with nanoscale resolution. The technique is first validated using the widely-used commercial biaxially oriented polypropylene, yielding consistent results with macroscopic ISPD. The technique is then applied to investigate polyvinylidene fluoride-based nanocomposites filled with barium titanate nanoparticles, revealing higher deep trap density around surface-modified nanoparticles, which correlates well with its increased breakdown strength. This technique thus provides a powerful spatially resolved tool for understanding the microscopic mechanism of dielectric breakdown of nanocomposites.
研究领域:
材料科学
·
物理学
✓ 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）