APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Chao Fan,Yaheng Zhang,Shouqiang Huang,Xinyu Yang,Jun Wang,Zhichun Li,Songjian Zhao,Weilin Zheng,Guobiao Li
Metal halide perovskites are restricted by their stability and environmental detriment due to the participation of expensive and toxic reagents. We have selected a green dry mechanical grinding method to synthesize the perovskite materials, and with the introduction of Zn powder (CZ), most of the bulk CsPbBr 3 /Cs 4 PbBr 6 phases (pure C) are converted to Cs 2 ZnBr 4 , which separates the remaining CsPbBr 3 NCs to form heterostructures on the surface ZnO layer of Zn. The photoluminescence (PL) of the resultant CZ samples first increases and then decreases as the Zn dosage changes, and the PL intensity of the optimum sample with 10 mmol of Zn (CZ10) increases to about 8 times that of pure C. The largely enhanced PL of CZ10 is originated from the remaining CsPbBr 3 NCs promoted by the weakened charge transfer from CsPbBr 3 to Cs 2 ZnBr 4 and the metallic Zn due to the formation of a quasi-type I heterostructure of Cs 2 ZnBr 4 /ZnO. After the calcination treatment at 700 ℃ (CZ10-C700), 80% of PL is maintained, but the photostability of CZ10-C700 is greatly enhanced compared with that of CZ10, and 99.3% of PL is kept after 150 h illumination, which is attributed to the encapsulation protection of CsPbBr 3 /Cs 2 ZnBr 4 by the ZnO layer on Zn.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2018
·
IF 4.484
Xianwei Bai,Haizheng Zhong,Bingkun Chen,Cheng Chen,Junbo Han,Ruosheng Zeng,Bingsuo Zou
Pb-free inorganic–organic perovskite materials - C10H12N2MnBr4 (compound 1) and C5H6NMnBr3 (compound 2) - with different structures were obtained by using pyridine and manganese bromide as raw materials. The single-crystal X-ray diffraction analyses revealed their different lattices in space groups. Compound 1 - Mn tetra-Br-coordinated with two pyridines - presented an isolated mononuclear structure. Its temperature-dependent photoluminescence spectra exhibited an emission band at 523 nm from the lowest d–d crystal field transition of Mn and a higher energy emission at 493 nm from its vibronic state at low temperature. Compound 2 - Mn octahedra-Br-coordinated with a minor pyridine - face-shares with linear chains, which were separated by pyridine molecules. Its emission peak occurred at around 650 nm, in which ferromagnetism was observed. The lifetimes of d–d transition for a single manganese ion and the Mn cluster were presented.
研究领域:
材料科学
·
光学
·
无机化学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 24
·2041
·
IF 4.4
Yi Zhang,Huilong Chen,Junfeng Qu,Jiayu Zhang,Gavin Conibeer
The hot carrier multi-junction solar cell (HCMJC) is an advanced-concept solar cell with a theoretical efficiency greater than 65%. It combines the advantages of hot carrier solar cells and multi-junction solar cells with higher power conversion efficiency (PCE). The thermalization coefficient (Qth) has been shown to slow down by an order of magnitude in low-dimensional structures, which will significantly improve PCE. However, there have been no studies calculating theQthof MAPbBr3quantum dots so far. In this work, theQthvalues of MAPbBr3quantum dots and after BABr addition were calculated based on power-dependent steady-state photoluminescence (PD-SSPL). Their peak positions in PD-SSPL increased from 2.37 to 2.71 eV after adding BABr. The fitting shows that, after adding BABr, theQthdecreased from 2.64 ± 0.29 mW·K−1·cm−2to 2.36 ± 0.25 mW·K−1·cm−2, indicating a lower relaxation rate. This is because BABr passivates surface defects, slowing down the carrier thermalization process. This work lays the foundation for the theoretical framework combining perovskite materials, which suggests that the appropriate passivation of BABr has the potential to further reduceQthand make MAPbBr3QDs with BABr modified more suitable as the top absorption layer of HCMJCs.
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
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 19
·9743-9752
·
IF 11.301
Jun-Xing Zhong,Jin-Feng Liao,Yong Jiang,Lianzhou Wang,Dai-Bin Kuang,Wu-Qiang Wu
Organic small molecules like ammonium halide salts (AHSs) are widely used to suppress the non-radiative charge recombination of solution-processed halide perovskite films with defective surface and unfavorable energy levels for enhanced photovoltage, but more often than not at a cost of enlarging the band gap of perovskite materials, which limits the light absorption and thus, the photocurrent density. In addition, there is still a lack of fundamental understanding and visual characterization of the surface and bulk composition change upon subsequent surface treatment with heterogeneous ingredients. Herein, we report and identify that AHS soaking treatment enables the formation of δ-FAPbI3 on the surface of the perovskite film for defect passivation functions, thus reducing the interfacial recombination loss and increasing photovoltage. Meanwhile, the AHS molecules diffuse and alloy with the bulk perovskite material to reduce the band gap, red-shifting the absorption region and thus increasing the photocurrent. Blade-coated perovskite solar cells (PSCs) prepared via AHS treatment achieved a champion power conversion efficiency (PCE) of 21.9% with a high open-circuit voltage (Voc) up to 1.18 V under AM 1.5G sun illumination, which is remarkably higher than the pristine PSCs without any treatment (19.2%), and outperforms other blade-coated PSCs, regardless of their perovskite compositions. Surface treatment of perovskite films with functional, organic small molecules is a promising strategy for rational composition management and favorable gradient distribution, which are beneficial for realizing efficient and stable PSCs.
研究领域:
材料科学
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能源技术
·
光伏研究
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2022
·Vol. 32
·期 30
·2202245
·
IF 19.924
Tingting Liang,Xiaqing Zhang,Lijun Su,Ruilin Hou,Bingjun Yang,Junwei Lang,Shengrong Yang,Xingbin Yan
Perovskite materials can store charge through rapid oxygen anions intercalation. Although numerous perovskite materials owing to rich selections of A and B-site elements are reported as electrodes of supercapatteries, the effect of the crystal structure of perovskite materials on their electrochemical performance has never been studied so far. Herein, using SrCo 0.9 Mo 0.1 O 3− δ , SrFeO 3− δ , Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3− δ , and LaMnO 3− δ as research targets, it is proved that their corresponding cubic structure materials display the best electrochemical performance. And then, the origin of such superiority of cubic structure for SrCo 0.9 Mo 0.1 O 3− δ is explored through experimental investigations and theoretical calculations. The results show that the increase in the content of oxygen vacancies and the enhancement of B-O hybridization of cubic structure can optimize the electronic structure of the perovskite materials, thereby improving its conductivity and accelerating the reaction kinetics. The filtering strategy based on crystal structure proposed by this report will provide a new perspective to faster and more efficient choice of perovskite materials for supercapatteries.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Crystals
·
2024
·Vol. 14
·期 11
·1006
·
IF 2.4
Tingting Yan,Linan Liu,Dongyang Xi,Lei Sun,Dinghan Jin,Han Li
Cs2NaHoCl6, a double perovskite material, has demonstrated extensive application potential in the fields of anti-counterfeiting and optoelectronics. The synthesis of Cs2NaHoCl6crystals was achieved using a hydrothermal method, followed by the determination of their crystal structures through single crystal X-ray diffraction techniques. The material exhibits bright red fluorescence when exposed to ultraviolet light, confirming its excellent optical properties. An in situ high-pressure fluorescence experiment was conducted on Cs2NaHoCl6up to 10 GPa at room temperature. The results indicate that the material possibly undergoes a structural phase transition within the pressure range of 6.9–7.9 GPa, which is accompanied by a significant enhancement in fluorescence. Geometric optimization based on density functional theory (DFT) revealed a significant decrease in the bond lengths and crystal volumes of Ho-Cl and Na-Cl across the predicted phase transition range. Furthermore, it was observed that the bond lengths of Na-Cl and Ho-Cl reach an equivalent state within this phase transition interval. The alteration in bond length may modify the local crystal field strength surrounding Ho3+, consequently affecting its electronic transition energy levels. This could be the primary factor contributing to the structural phase transition.
研究领域:
材料科学
·
光学
·
凝聚态物理
✓ 已验证
DOI
高影响因子
FERROELECTRICS
·
2019
·
IF 0.697
Weiwei Li,Jiangtao Zeng,Liaoying Zheng,Huarong Zeng,Chunbo Li,Abdelhadi Kassiba,Chulhong Park,Guorong Li
CH3NH3PbI3 (MAPbI3) has attracted great interest of researchers for its impressively high efficiency in solar cells. Researchers have debated whether or not MAPbI3 is ferroelectric for a long time. In this work, the ferroelectric hysteresis loops, dielectric properties, the real part of impedance and domain structure of the samples synthesized in ambient air (not in a glove box) are investigated. No domain switching current is found in the pellets and films at room temperature, but ferroelectric domains are observed in the films with in plane and out of plane conurations. The dielectric constant as a function of temperature shows that there is no ferroelectric to paraelectric phase transition. The complexity and uncertainty concerning the ferroelectricity of the samples synthesized in ambient air are the same as those synthesized in a glove box.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2023
·
IF 2.8
Kaili Liang,Yang Liu,Lishuang Hu,Jiashun Liang,Tiancheng Lv,Yanping Wang,Shuangqi Hu
Micron-sized zirconium (μZr) is a viable alternative fuel source for high-energy propellants. To explore the combustion performance of Zr-containing DAP-4-based composites, DAP-4/Zr and F/DAP-4/Zr composites were designed. The results showed that the optimized composite had high combustion performance. When DAP-4/Zr was 54:46, the sample had the highest combustion heat and the fastest flame spreading velocity. The combustion time of F/DAP-4/Zr became longer after adding F 2602 , and the flame spread was the fastest when F/DAP-4/Zr was 10:48.6:41.4. The results indicate that the introduction of μZr as a fuel in DAP-4 can improve the material's energy density and combustion characteristics.
研究领域:
材料科学
·
燃烧与推进
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Ze Wei,Xueqing Xiong,Xiyong Chen,Juntao Pan,Donglin Cai,Xiaomei Huang,Gang Han,Yihui Liu,Zezuo Jiang,Toyohisa Fujita
The effects of Sr doping on the crystal structures, thermal expansion behaviors, defect chemistries , electrical and electrochemical properties of the perovskite materials, La 0.5 Gd 0.5 Ba 1− x Sr x Co 2 O 5+ δ (LGBCOSr- x, x =0–0.5), were systematically analyzed and discussed. The X-ray diffraction (XRD) investigation revealed that LGBCOSr- x undergoes a phase transformation from tetragonal ( x =0.1) to cubic ( x =0.5), and the materials exhibit good thermochemical compatibility with Ce 0.9 Gd 0.1 O 1.95 (GDC) under 1100 °C. Partial replacement of Ba with Sr is found helpful in decreasing the thermal expansivity of LGBCOSr- x and increasing the ability of oxygen vacancy formation in the materials. The latter could be attributed to the enhancement in the overall electrical conductivity and oxygen transport process in terms of low cathodic polarization resistance in LGBCOSr- x materials with high Sr doping content. Further analysis on the AC impedance spectroscopy assisted with the DRT (distribution of relaxation times) methodology suggested that the charge transfer sub-process is a predominant step in the oxygen transport processes across the LGBCOSr- x materials. These findings indicate that La 0.5 Gd 0.5 Ba 1− x Sr x Co 2 O 5+ δ is a promising cathode material for intermediate temperature solid oxide fuel cells.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Technologies
·
2020
·Vol. 5
·期 8
·2000260
·
IF 5.969
Zhiyong Liu,Xingyue Liu,Bo Sun,Xianhua Tan,Haibo Ye,Jianxin Zhou,Zirong Tang,Tielin Shi,Guanglan Liao
Photodetectors are essential parts of wireless optical communication system for obtaining high fidelity signal transmission, which mainly relies on expensive and energy-consuming Si, GaN, and InGaAs based photodiodes. The emerging organic–inorganic metal halide perovskite materials, with the merits of low-cost, strong optical absorption, superior charge transport, and so on, are widely investigated in photodetection applications. Herein, a Cu ion induced p-type doping strategy for perovskite film is proposed to facilitate hole transport, passivate trap states, avoid charge accumulation, and suppress recombination of photogenerated carriers, contributing to an enhanced photoelectric performance for self-powered hole-conductor-free devices. The optimal device shows a highest responsivity of 0.37 A W −1 , detectivity of 1.06 × 10 12 Jones, linear dynamic range of over 101 dB, and an ultimate photoresponse rate approaching 5 µs. Moreover, an optical communication system integrated with the perovskite photodetector as light signal receiver for transmitting digital signals is demonstrated, in which characters can be transmitted accurately, and audio signal is recovered with high fidelity. The results suggest that with proper chemical modification, perovskite materials are promising alternative to inorganic semiconductors for efficient photodetection in advanced integrated optical communication system.
研究领域:
材料科学
·
光学工程
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
AIP Advances
·
2018
·Vol. 8
·期 3
·
IF 1.653
Song Kena,Wu Yinghui,Chen Xi,He Yi,Liu Liyu,Chen Guo,Liu Ruchuan
We report Atomic Force Microscopy (AFM) and Scanning Kelvin Probe Microscopy (SKPM) studies on the surface morphology and surface potential properties of CH 3 NH 3 PbI 3 , CH 3 NH 3 PbI 3 -x Cl x , CH 3 NH 3 PbI 3 -x Br x and CH 3 NH 3 PbBr 3 -x Cl x , respectively. For CH 3 NH 3 PbI 3 rod structure, its surface potential is independent of the precursor concentration, suggesting a robust electronic feature. Surface potential studies of CH 3 NH 3 PbI 3 particle reveal that the Fermi level within CH 3 NH 3 PbI 3 is strongly influenced by the substrate. In the case of CH 3 NH 3 PbI 3 -x Cl x , its surface potential depends on precursor concentrations and we suspect that chlorine concentrated solutions might lead to more chlorine incorporation in the final products, thus lowering its Fermi level. Also, we studied the surface potentials of CH 3 NH 3 PbI 3 -x Br x and CH 3 NH 3 PbBr 3 -x Cl x with specified halide ratios. The surface potential differences between different samples are related to their work function variations. These results are helpful to the understanding of the structural and electronic properties of perovskite materials.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2020
·Vol. 22
·期 30
·17299-17305
·
IF 3.43
Chenyang Zhou,Ya Chu,Linlin Ma,Yingqian Zhong,Chao Wang,Yalan Liu,Haoyue Zhang,Beibei Wang,Xia Feng,Xi Yu,Xiaotao Zhang,Yan Sun,Xiaozeng Li,Guangjiu Zhao
In this work, we introduced halogen-substituted chiral molecules as A-site cations to synthesize a series of novel organic–inorganic hybrid two-dimensional (2D) chiral perovskite materials (R-X-p-mBZA)2PbBr4 (X = H, F, Cl, Br; p: para-position; mBZA = α-methylbenzylamine) for the first time. This halogen-substituted cation strategy collectively solved problems of narrow emission, weak chirality and low photoluminescence quantum yield (PLQY) for the emerged chiral perovskites. Photoluminescence (PL) spectra are significantly broadened due to the additional emission from self-trapped excitons (STEs) besides free excitons (FEs) states modulated by introducing significant disorder to the Pb–Br–Pb angle. The chirality of A-site chiral molecules is transferred and amplified to entire perovskite materials by fixing the chiral molecules at A-site via the interaction of halogen atoms. Furthermore, their PLQYs are improved with the reduction of energy gap and inhibition of the non-radiative transition from STEs to ground state. The halogen-substituted A-site cation strategy can be performed to develop organic–inorganic hybrid chiral perovskites with various optoelectronic applications.
研究领域:
材料科学
·
光学
✓ 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）