SOLAR ENERGY
·
2020
·
IF 4.608
Bing Liu,Rongli Cui,Huan Huang,Xihong Guo,Shouwei Zuo,Jinquan Dong,Huanli Yao,Ying Li,Dangui Zhao,Jiahao Wang,Jing Zhang,Yu Chen,Junliang Yang,Baoyun Sun
The crystal structure of perovskite has a significant influence on the photovoltaic performance and stability of perovskite solar cells (PSCs). Pb 4+ is introduced into CH 3 NH 3 PbI 3 (MAPbI 3 )-based PSCs by participating the octahedral [PbI 6 ] 4- structure, then to induce the formation of stronger Pb-I bond and reduce [PbI 6 ] 4- octahedron distortion, which would improve structural symmetry, decrease the degree of disorder and be beneficial to the crystallization of perovskites . Synchrotron based X-ray absorption fine spectroscope (XAFS) revealed that the existence of higher valence state lead could be realized by doping Pb 4+ directly or induced by electron withdrawing group, in consequence the [PbI 6 ] 4- octahedral structure becomes more stable. Grazing incidence X-ray diffraction (GIXRD) especially demonstrates that Pb 4+ with appropriate proportion may well replace part of Pb 2+ to form an uniform phase in the primal perovskite structure to improve the crystallization on the surface and homogeneous out-of-plane (OOP) ordered crystal accumulation in the bulk, which is also important for improving the efficiency and stability of PSCs. As a result, a power conversion efficiency (PCE) exhibits a 42.1% increase with the doping of 0.03% PbF 4 and 0.075% PCBM compared with a pristine device and its stability improves markedly after 30 days of storage in ambient atmosphere.
研究领域:
材料科学
·
能源研究
✓ 已验证
DOI
高影响因子
MICRON
·
2018
·
IF 1.728
Xuanyu Chen,Zhiwei Wang
Chemical and structural instabilities of lead halide perovskites remain a major obstacle to their large-scale applications in photovoltaic solar cells and optoelectronic devices. Herein we report on a comparative investigation of electron beam irradiation effects on (all-inorganic) CsPbI 3 and (organic-inorganic hybrid) CH 3 NH 3 PbI 3 halide perovskite thin films by transmission electron microscopy. Upon continuous electron beam irradiation with high dose rates, CsPbI 3 exhibits rather rapid morphological change and compositional degradation within irradiated regions, which are attributed to the radiolysis effect and probably assisted by electron beam heating and Coulomb forces. In contrast, for the freestanding, polycrystalline CH 3 NH 3 PbI 3 thin films, significant structural damage mainly occurs on/outside the periphery of the irradiated regions, while, within the irradiated areas, the structural configurations appear rather intact. The electron beam induced electric field effect is suggested to be the primary reason for the unusual damage phenomenon. The building up of induced electrical fields in CH 3 NH 3 PbI 3 is probably pertinent to its some unusual structural properties (e.g., rotational dynamics of organic cations), but should be also promoted by the unavoidable modifications of physical properties during the film preparation and electron beam focusing. The study provides an insight for exploring the fundamental origin of structural instabilities and property degradation of halide perovskites.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 27
·13585-13593
·
IF 11.301
Xi Yuan Feng,Kar Wei Ng,Shuang Peng Wang,Wen Zhou Chen,Zhen Zhong Zhang,Wei Chen,Yun Yang Zhao,Bao Tu,Zi Kang Tang,Hui Pan,Zhu Bing He
The amine-induced very fast liquefaction and recrystallization (L&R) process on organic–inorganic hybrid perovskites has been demonstrated to be an effective way to improve the quality of the as-deposited MAPbI3 films and increase the feasibility of preparing large area perovskite solar cells (PSCs). Despite the effectiveness, the reaction mechanism of the L&R process is yet to be well understood. In this work, we investigate the fundamental influences of amines on the structural change of MAPbI3 perovskite by studying the reaction between ammonia and a bulk MAPbI3 crystal. By employing various techniques including in situ X-ray diffraction, Raman spectroscopy and Fourier transform infrared spectroscopy, we find that NH3 effectively substitutes iodine in the perovskite crystal lattice, transforming the 3-dimensional (3D) lattice into a MAPb(NH3)nI3 coordination complex-based system. The resulting coordination complex octahedral structures are only held together by weak forces of attraction, leading to the experimentally observed L&R process. First-principles calculations further confirm the feasibility of such L&R at room temperature. As a proof of concept, we demonstrated the use of liquefaction for substrate recycling of MAPbI3 based solar cells with ammonia. Our results here provide deep insights for understanding the interaction mechanism, which can surely provide important guidance on improving the quality of perovskite films and related devices, as well as the recycling of toxic lead for long-term sustainability.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2012
·Vol. 24
·期 2
·658-661
·
IF 1.076
Yang Shihua,Xu JinBao,Gao Bo,Wang Lei,Chen Jing,Chen Xueying
Polycrystalline Ba 0.85 Ca 0.15 Ti 0.9 Zr 0.1 O 3 (BCZT) thin films with (100) preferential and random orientation are prepared on the LaNiO 3 electrodes coated on Si substrates by chemical solution deposition process. The results show that the two types of films stabilize in the pure perovskite structure. The ferro-paraelectric phase transitions of two types of films occur at the temperature ranges of 280.2–297.8 K and 278.4–287.6 K, respectively. The dielectric constant, relaxation time and tunability of the random orientation film are smaller than those of the (100) preferential film but both almost have the similar leakage current characteristics. The mechanism associated with the change of the electrical properties of the thin films is also discussed.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 2
·1-10
·
IF 2.8
Guan Yeqing,Zhang Jinxian,Wang Fenglin,Li Wei,Mao Haijun,Liu Zhuofeng,Zhang Weijun,Chen Xingyu
The Ca 0.245 Li 0.325 Nd 0.395 Ti 1− x Sn x O 3 ( x = 0–0.12) ceramics were prepared by the traditional solid-state reaction method. The effects of Sn 4+ substitution for Ti 4+ on the phase composition, microstructure, and microwave dielectric properties of Ca 0.245 Li 0.325 Nd 0.395 Ti 1− x Sn x O 3 (CLNTS x ) were investigated in this work. The X-ray diffraction results showed that the ceramics had a single orthorhombic perovskite structure when x = 0–0.09. However, a secondary phase SnO 2 was observed with x > 0.09. The SEM micrographs indicated that the proper Sn 4+ substitution for Ti 4+ promoted the grain growth and homogenization. The analysis results of Raman spectroscopy revealed the correlation between vibration modes and microwave dielectric properties of CLNTS x ceramics with different Sn 4+ contents. The degree of cation order was related to the full width at half maximum (FWHM) of the Raman spectrum, and a lower FWHM value indicates higher cationic order and Q × f 0 value. The excellent microwave dielectric properties with ε r = 98, Q × f 0 = 3320 GHz, and τ f = 2.6 ppm/°C were obtained in the ceramics with x = 0.09 sintered at 1350 °C for 4 h.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2024
·
IF 4
Bin Li,Rongbo Ma,Chong Yang,Bin Cao,Chaoyong Deng,Weichao Huang
Novel CaSrLaSbO 6 : Mn 4+ red-emitting phosphors with double perovskite structure were successfully synthesized by the high-temperature solid-phase method. CaSrLaSbO 6 :Mn 4+ phosphor showed a broad excitation band with different excitation peaks from 250 nm to 600 nm owing to the Mn 4+ -O 2- charge transfer and 4 A 2g → ( 4 T 1g , 2 T 2g , and 4 T 2g ) transitions of Mn 4+ ions and exhibited intense deep-red emission at 678 nm attributed to the 2 E g → 4 A 2g transition of Mn 4+ ions. To further enhance the performance of the phosphor, a cation doping method was adopted in this paper to synthesize CaSrLa 1- x Ln x SbO 6 : Mn 4+ (Ln = Gd, Y) phosphors. The luminescence intensity of the samples was enhanced after doping with different cations, and the related mechanism was discussed. In addition, the microstructure and crystal field environment were systematically investigated. The luminescence intensity of the CaSrLa 0.85 Y 0.15 SbO 6 : Mn 4+ phosphor was about 1.82 times higher than that of CaSrLaSbO 6 : Mn 4+ phosphor. The emission spectrum of the sample matched well with the absorption band of plant pigments. Furthermore, the plant growth LEDs and light-conversion film were prepared by using the optimized CaSrLa 0.85 Y 0.15 SbO 6 : Mn 4+ . The results indicate that the designed phosphors have great potential applications in agricultural cultivation.
研究领域:
材料科学
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Xin Zhang,Yiwen Wang,Orest M. Ivasishin,Jiaqi Zhang,Long Yuan
Inorganic thermochromic materials exhibit a tunable color gamut and a wide chromatic temperature range, indicating their potential for intelligent adaptive applications in thermal warning, temperature indication, thermal regulation, and interactive light-to-thermal energy conversion. However, most metal-oxide-based thermochromic materials show weak chromaticity adaption with the change of temperature, which needs further understanding of the microscopic principle to clarify the potential route to improve the contrast and identifiability for fabricating better thermochromic materials. Using perovskite-structure (AMO3) alkaline earth metal stannate (Ba1–xSrxSnO3, 0.0 ≤ x ≤ 1.0) as a model system, this paper reports for the first time the mechanism of the properties of thermally induced defect-enhanced charge transfer-type (CTT) thermochromic materials and the strategy for regulating their thermochromic properties by A-site cations. BaSnO3 exhibits continuously reversible thermochromic properties with high contrast from weak light yellow (b* = 11) to strong bright yellow (b* = 58) between room temperature and 550 °C. In-situ high-temperature X-ray diffraction (in-situ XRD), in-situ UV–vis absorption spectroscopy (in-situ UV–vis), thermogravimetric (TG), and electron paramagnetic resonance (EPR) spectra indicate that this excellent thermochromic phenomenon is attributed to the weakening of Sn–O bond hybridization at high temperatures, as well as the formation of a large number of oxygen vacancies at the top of the valence band, and the enhanced charge transfer resulting from the generation of impurity levels in the Sn2+ 5s2 intermediate. Replacing Ba2+ by Sr2+ in Ba1–xSrxSnO3 successfully tuned the thermochromic properties, which is attributed to the Sr2+ doping level-directed oxygen defect concentration and deoxygenation rate. The demonstrated defect-enhanced charge transfer behavior promotes a feasible route for lattice oxygen-mediated thermochromic materials and provides a fundamental relationship between thermally induced defects and colorimetry.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2023
·Vol. 16
·期 11
·4044
·
IF 3.4
Runyu Mao,Deyi Zheng,Qiyun Wu,Yuying Wang,Chang Liu
The (Ba0.85Ca0.15) (Ti0.90Zr0.10)O3+xY3++xNb5+(abbreviated as BCZT-x(Nb + Y),x= 0 mol%, 0.05 mol%, 0.1 mol%, 0.2 mol%, 0.3 mol%) lead-free piezoceramics samples were prepared by a traditional solid-state sintering method. And the effects of Yttrium and Niobium elements (Y3+and Nb5+) co-doping on the defect, phase and structure, microstructure, and comprehensive electrical properties have been investigated. Research results show that the Y and Nb elements co-doping can dramatically enhance piezoelectric properties. It is worth noting that XPS defect chemistry analysis, XRD phase analysis and TEM results together show that a new phase of double perovskite structure Barium Yttrium Niobium Oxide (Ba2YNbO6) is formed in the ceramic, and the XRD Rietveld refinement and TEM results show the coexistence of the R-O-T phase. Both these two reasons together lead to significant performance improvements of piezoelectric constant (d33) and planar electro-mechanical coupling coefficient (kp). The functional relation between temperature and dielectric constant testing results present that the Curie temperature increases slightly, which shows the same law as the change of piezoelectric properties. The ceramic sample reaches an optimal performance atx= 0.1% of BCZT-x(Nb + Y), whered33= 667 pC/N,kp= 0.58,εr= 5656, tanδ= 0.022,Pr= 12.8 μC/cm2,EC= 2.17 kV/cm,TC=92 °C, respectively. Therefore, they can be used as potential alternative materials to lead based piezoelectric ceramics.Keywords:BCZT piezoelectric ceramics;double perovskite structure;phase structure;piezoelectric properties
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
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2022
·Vol. 33
·期 27
·21976-21984
·
IF 2.779
Sha Ke,Lin Feng Li,Liu Bing,Song Kai Xin,Zhang Jia Heng
Dense (Sr 1 − x Ca x ) 2 (Ti 1 − x Sn x )O 4 ( x = 0.0, 0.05, 0.10, 0.15) ceramics were synthesized by a standard solid-state reaction method. The formation of solid-solution with an I 4/ mmm space group was revealed from the X-ray diffraction patterns and Rietveld refinement results. The variation of the microwave dielectric properties was systematically analyzed using the dielectric polarizability and complex chemical bond theory. The dielectric constant ( ε r ) was mainly determined by the ionic polarizability per unit volume. Qf value was closely associated with the increasing amount of Sr 3 Ti 2 O 7 secondary phase and the declined lattice energy. Meanwhile, the variation of Qf value was further analyzed by extrapolating the intrinsic dielectric loss from the infrared reflectivity spectra. τ f value was successfully adjusted toward zero, which could be explained by the enhanced bond energy. The optimal microwave dielectric properties were achieved at x = 0.10, with ε r = 33.6, Qf = 73,150 GHz, and τ f = 115 ppm/°C.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Leilei Li,Jing Wang,Qilong Guo,Yongheng Yang,Zongmo Shi,Jie Xu,Wanzhi Cao,Feng Gao
Two-dimensional platelets of the perovskite-structured PbTiO 3 were synthesized from a layer-structured PbBi 4 Ti 4 O 15 precursor, using a topochemical microcrystal route. The PbBi 4 Ti 4 O 15 precursor showed a high aspect ratio with an average size of ∼7.74 μm and thickness of ∼0.29 nm. Later, PbTiO 3 platelets coexisting with Pb 4 Bi 4 Ti 7 O 24 mesophase were obtained, which had a more stable Aurivillius structure and was difficult to completely convert to the perovskite structure during topochemical microcrystal conversion. The reason that the Pb 4 Bi 4 Ti 7 O 24 mesophase coexisted in PbTiO 3 platelets was deeply discussed. Both the crystal structure difference between the unit cell parameters for (Pb 4 Bi 2 Ti 7 O 22 ) 2- and the thickness for the (Bi 2 O 2 ) 2+ layer, and the stability of (Bi 2 O 2 ) 2+ layer were used to analyze the existence of Pb 4 Bi 4 Ti 7 O 24 phase. However, the result showed that the stability of (Bi 2 O 2 ) 2+ layer was the dominant reason, because the [OBi 4 ]/[OPb 4 ] tetrahedron formed in the (Bi 2 O 2 ) 2+ layer due to the similar chemical properties of Pb 2+ and Bi 3+ . The work provided deep theoretical guidance to fabricate anisotropic perovskite platform-based topchemical microcrystal conversion mechanisms.
研究领域:
材料科学
·
无机化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Yuehua Li,Shaoxian Li,Weiwei Meng,Lei Dai,Ling Wang
A series of impedancemetric sensors for ammonia detection were fabricated using yttrium stabilized zirconia (YSZ) electrolyte and La n+1 Ni n O 3n+1 (n = 1, 2, and 3) sensing electrodes. The sensing materials with layered perovskite structure were prepared using in-situ impregnation method and well-dispersed in YSZ porous skeleton after calcination at 900 °C. The sensing performances of the sensors with La n+1 Ni n O 3n+1 sensing electrodes were investigated using the impedancemetric modulus |Z| and phase angle Θ as response signals, respectively. The results show that the sensor with La 2 NiO 4+ δ sensing electrode exhibits the higher response values and sensitivity compared to the sensor using La 3 Ni 2 O 7- δ or La 4 Ni 3 O 10- δ sensing electrodes, which is attributed to the largest NH 3 adsorption capacity of La 2 NiO 4+ δ . The response signals |Z| or Θ of the La 2 NiO 4+ δ based sensor linearly depend on NH 3 concentrations. The sensor hardly is insensitive to co-existing gases such as CO 2 , CH 4 , H 2 and relative humidity, but NO or NO 2 causes a positive error.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Jian Guo,Zhiming Geng,Lanji Wen,Ningchong Zheng,Mingqian Yuan,Ke Wang,Shan-Tao Zhang
In conventional knowledge, ferroelectric solid solutions were formed between members belonging to the same crystal structure family. Since both tungsten bronze and perovskite structures are constructed by connecting the corner-sharing oxygen octahedra, it offers a possibility for formatting an unusual solid solution between these two families. Herein, (1 – x)Sr0.6Ba0.4Nb2O6-xBaTiO3, (1 – x)SBN-xBT, solid solutions were synthesized and the solution mechanism was resolved from a structure viewpoint. With increasing BT content, the solid solution persists of tetragonal tungsten bronze structure, but the lattice parameter a (= b) decreases whereas c increases, resulting in the significant reduction of grains anisotropy. The ferroelectric–relaxor phase transition temperature shows a monotonic increase as x increases. However, the ferroelectricity evolution is not monotonous as a function of BT content because of the competitive effects of Ba and Ti on the property. As a result, the x = 0.10 ceramic shows the strongest ferroelectricity and a remarkable electrocaloric effect of 1.4 K near room temperature. This work challenges the traditional view of solid solution formation and provides an alternative way to modulate the structure and properties of ferroelectrics.
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）