Journal of Materials Chemistry C
·
2022
·Vol. 10
·期 40
·15000-15007
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IF 8.067
Han Zhang,Wenqing Zhu,Lu Huang,Chen Yi,Ruilin Chen,Yipeng Chen,Jun Li
The hole-injection layer (HIL) plays a critical role in the efficiency and stability of organic light-emitting diodes (OLEDs). However, inorganic HIL materials, such as transition metal oxides (TMOs), usually suffer the problems of low conductivity and mismatched work function at ITO/hole-transport layer (HTL) interfaces, which limits the hole-injection in OLEDs. In this paper, a gold (Au) and lithium (Li) co-doping strategy has been employed to fabricate a vanadium oxide (VOx) HIL through solution processing at low temperature for improving device performance. Compared to non-doped VOx and Au-doped VOx films, co-doping with an optimal molar ratio of Au and Li endows the VOx films with both higher electrical conductivity and proper work function matching with the ITO anode and HTL, which leads to efficient hole-injection and improved carrier balance in the device with the Au and Li co-doped VOx (Au,Li:VOx) HIL. As a result, the device with the Au,Li:VOx HIL shows a peak power efficiency of 50.2 lm W−1 and a maximum external quantum efficiency (EQE) of 19.9%, which are superior to those of the counterpart with the VOx HIL (34.4 lm W−1 and 18.1%). Meanwhile, the device shows distinguished stability. This work indicates that Au and Li co-doping is an effective method to obtain an efficient VOx HIL with excellent hole-injection ability, which provides a promising avenue to enhance OLED performance.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2020
·Vol. 31
·期 3
·2100-2110
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IF 2.22
Fan Lele,Liu Zhonghu,Zhu Yiyu,Wang Zhiqiang,Zhao Sihan,Zhu Lei,Zhang Qinfang
In this work, Li x BiO y compounds were synthesized via a facile calcination method. It was surprising that the as-prepared Li 7 BiO 6 compounds transformed into Li-doping tetragonal Bi 2 O 3 phase after undergoing water washing disposal, which was well verified by combining XRD and HR-TEM. In addition, the energy bandgap of prepared compound was derived based on UV–Vis diffuse reflectance spectrum and results indicate the formation of a lower band gap when increasing Li dopant concentration. Moreover, the Li-doping tetragonal Bi 2 O 3 exhibited high visible light-driven photocatalytic activity and the methylene blue can be well degraded in 10 min. The enhanced photocatalytic activity was ascribed to the improvement of light response and charge transfer. Our current work will boost the development of photocatalysis and bring insight into other Li x MO 6 (e.g., Li 6 WO 6 , Li 7 TabO 6 , Li 7 NbO 6 , Li 8 ZrO 6 ) compounds to extend their photocatalytic application.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Baisheng Ma,Jincheng Li,Yan Zhu,Kewei Wang,Boyan Sun,Ke Ren
In this paper, the reactive flash sintering method was adopted to synthesize a series of Li x (CoCrFeMnNi)O y oxides with x in the range of 0–1. The phase compositions and electrical conductivities of the oxides at different Li incorporation level were characterized. A single phase of spinel structure ( Fd-3m ) was obtained for the sample (CoCrFeMnNi) 3 O 4 . With incorporation of Li, the phase transformed into Rock-salt structure ( Fm-3m ) and then layered structure ( R-3m ). The ionic and electronic conductivities of the samples were characterized by impedance spectrometry. The ionic and electronic conductivities of the samples decreased with increasing Li incorporation level at first along with the spinel to Rock-salt structure transformation, and then increased with further increasing Li incorporation level along with the Rock-salt to layered structure transformation.
研究领域:
材料科学
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电化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2021
·
IF 5.816
Chengbao Liu,Dongchen Shen,Zhengkai Tu,Song Li
Li + doping is regarded as an effective strategy to enhance the room-temperature hydrogen storage of metal-organic frameworks (MOFs). In this work, Li + is doped into both MIL-100(Fe) and MIL-100(Fe)/graphene oxide (GO) composite, and it is demonstrated that the hydrogen uptake of Li + doped MIL-100(Fe)/GO (2.02 wt%) is improved by 135% compared with Li + doped MIL-100(Fe) (0.86 wt%) at 298 K and 50 bar, which is ascribed to its higher isosteric heat of adsorption (7.33 kJ/mol) resulting from its more accessible adsorption sites provided by doped Li + ions and ultramicropores. Grand canonical Monte Carlo (GCMC) simulation reveals that Li + ions distributing in the interface between MIL-100(Fe) and GO within MIL-100(Fe)/GO composite is favorable for hydrogen adsorption owing to the increased number of adsorption sites, thus contributing to the enhanced hydrogen storage capacity. These findings demonstrate that MIL-100(Fe)/GO is a more promising Li + doping substrate than MIL-100(Fe).
研究领域:
材料科学
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能源化学
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2016
·Vol. 99
·期 7
·2354-2360
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IF 2.787
Dong-Sheng Yin,Zhi-Hao Zhao,Ye-Jing Dai,Zhe Zhao,Xiao-Wen Zhang,Si-Hui Wang
By conventional ceramics sintering technique, the lead-free 0.85Bi 0.5 Na 0.5(1− x ) Li 0.5 x TiO 3 -0.11Bi 0.5 K 0.5 TiO 3 -0.04BaTiO 3 ( x =0–0.15) piezoelectric ceramics were obtained and the effects of Li dopant on the piezoelectric, dielectric, and ferroelectric properties were studied. With increasing Li addition, the temperature-dependent permittivity exhibited the normal ferroelectric-to-ergodic relaxor (FE-to-ER) transition temperature ( T FE - ER , abbreviated as T F-R ) decreasing down to room temperature. The increasing Li content also enhanced the diffuseness of the FE-to-ER transition behavior. For composition with x = 0.15, a large unipolar strain of 0.37% ( = S max / E max = 570 pm/V) was achieved under 6.5 kV/mm applied electric field at room temperature. Both unipolar and bipolar strain curves related to the temperature closely, and when the temperature reached the T F-R , the normalized strain achieved a maximum value (e.g., for x = 0.10, = 755 pm/V) owing to the electric-field-induced ER-to-FE state transition.
研究领域:
材料科学
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电子工程
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产品关联
DOI
高影响因子
Journal of Advanced Dielectrics
·
2023
·
IF 3.1
Xinyu Bu,Changhong Yang,Mengjia Fan,Wenxuan Wang,Xiujuan Lin,Shifeng Huang
Lead-free ( K 0 . 5 Na 0 . 5 )NbO 3 (KNN) and Li 0 . 0 6 ( K 0 . 5 Na 0 . 5 ) 0 . 9 4 NbO 3 (LKNN) thin films were fabricated by a sol-gel method. The effects of Li substitution on crystal structure, microstructure and electrical properties of KNN film were systematically studied. Li doping can enhance the ferroelectric and piezoelectric properties of KNN film. Compared with pure KNN film, the LKNN film possesses larger remanent polarization ( P r ∼ 9.3 μ C/ cm 2 ) and saturated polarization ( P s ∼ 41.2 μ C/ cm 2 ) and lower leakage current density ( ∼ 1 0 − 5 A/ cm 2 at 200 kV/cm). Meanwhile, a typical butterfly shaped piezoelectric response curve is obtained in the LKNN film with a high piezoelectric coefficient ( d 3 3 ∼ 105 pm/V). Excellent fatigue resistance ( ∼ 1 0 9 switching cycles) and aging resistance ( ∼ 180 days) demonstrate the long-term working stability of LKNN film. These findings indicate that KNN-based lead-free piezoelectric films have a broad application prospect in microelectromechanical systems (MEMS).
研究领域:
材料科学
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物理学
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DOI
高影响因子
Journal of Applied Biomaterials & Functional Materials
·
2022
·
IF 2.744
Chengwu Lu,Linfeng Wang,Libao Zhang,Chaghui Xue,Hong Ye,Xiaojie Chen,Jianbin Wu,Jin Xiao
Osteoporotic fractures seriously endanger the elderly quality of life, especially postmenopausal women. Currently, calcium phosphate cement (CPC) is one of the materials used for the treatment of osteoporotic fractures. This study intends to investigate the biological effects of lithium (Li)-doped CPC. Li was dissolved into ultrapure water as curing solution to prepare CPC@Li composite material. Li did not affect the morphology of CPC. CPC@Li composite showed a sustained release of Li in 14 days. Compared with CPC, CPC@Li promoted the adhesion, proliferation, and osteogenic differentiation of rat bone marrow stem cells. The result of femur implantation in an osteoporosis mouse model showed that a larger amount of new bone was formed surrounding the CPC@Li implant and closely to the implant surface, indicating favorable osteogenesis and osteointegration capabilities. Li-doped CPC is promising to be used in clinic for its enhanced bone regeneration ability.
研究领域:
生物材料学
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骨科医学
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再生医学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Jun Cong,Shao-hua Luo,Peng-yu Li,Xin Yan,Li-xiong Qian,Sheng-xue Yan
Na 3 V 2 (PO 4 ) 3 (NVP) has become a hot material in the research field of sodium-ion batteries (SIBs) as a result of its unique structural advantages. Unfortunately, the poor electronic conductivity and ion diffusion ability fundamentally limit the practical development of NVP. Considering the above defects, a series of Li + doped Na 3−x Li x V 2 (PO 4 ) 3 /C cathode materials for SIBs are synthesized through hydrothermal assisted sol–gel method. The cell volume steadily decline with the raise of Li + doping amount, which is consistent with the usual doping effect. Moreover, with the increase of lithium doping amount, Li + preferentially occupies Na (2) site and then occupies Na (1) site. Through the first principles calculation, it is clear that the introduction of Li + can significantly reinforce the conductivity of the material system and diminish the electron localization phenomenon. The analysis of (1 1 6) crystal plane by TEM shows that Li doping will reduce the interplanar spacing. The change of V valence during the charge–discharge process of Na 2.8 Li 0.2 V 2 (PO 4 ) 3 /C is consistent with that of NVP by V element XANES characterization. There is no conventional phase transition phenomenon in the ex-situ XRD high-voltage charging state. The above facts indicate that lithium doping obtains a stable solid solution NVP. The electrochemical test results show that Na 2.8 Li 0.2 V 2 (PO 4 ) 3 /C can provide an amazing reversible capacity of 116.9 mAh/g (theoretical capacity of 117 mAh/g) and capacity retention rate of 99.82 % after 500 cycles. GITT results show that Li + can significantly increase the Na + diffusion coefficient of the material. Such excellent electrochemical performance is attributed to the fact that the doping of Li + activates the activity of Na + in Na (2) site and improves the reaction efficiency.
研究领域:
材料科学
·
电化学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Yanchun Yang,Xiaojiao Kang,Lijian Huang,Daocheng Pan
Alkali metal doping plays a crucial role in fabricating high-performance Cu(In,Ga)(S,Se)2 and Cu2ZnSn(S,Se)4 (CZTSSe) thin film solar cells. In this study, we report the first experimental observation and characterizations of the alloyed LixCu2–xZnSn(S,Se)4 thin films. It is found that Cu+ ions in Cu2ZnSn(S,Se)4 thin films can be substituted with Li+ ions, forming homogeneous LixCu2–xZnSn(S,Se)4 (0 ≤ x ≤ 0.29) alloyed thin films. Consequently, the band gap, conduction band minimum, and valence band maximum of LixCu2–xZnSn(S,Se)4 thin films are profoundly affected by Li/Cu ratios. The band alignment at the LixCu2–xZnSn(S,Se)4/CdS interface can be tuned by changing the Li/Cu ratio. We found that the photovoltaic parameters of the LixCu2–xZnSn(S,Se)4 solar cell devices are strongly influenced by the Li/Cu ratios. Besides, the lattice constant, carrier concentration, and crystal growth of LixCu2–xZnSn(S,Se)4 thin films were studied in detail.
研究领域:
材料科学
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太阳能技术
·
半导体物理
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DOI
高影响因子
OPTICAL MATERIALS
·
2021
·
IF 3.08
Chen Yi,Wenqing Zhu,Ruilin Chen,Lu Huang,Kuangyu Ding,Jun Li
The hole-injection layer (HIL) plays an important role in the electroluminescent property of organic light-emitting diodes (OLEDs). In this paper, Li-doped VO x was prepared by solution processing under low-temperature annealing conditions and used as a new kind of HIL in OLEDs. It demonstrated the best phosphorescent OLED performance when the molar ratio of Li:VO x was 3%. The turn-on voltage was 3.7 V, the maximum current efficiency (CE) was 69.5 cd A −1 and the maximum power efficiency (PE) was 48.4 lm∙W −1 . In contrast to the OLEDs with pristine VO x as HIL, the CE and PE of the OLEDs with Li:VO x were increased by 14.7% and 40.7% respectively. Based on the Fowler-Nordheim tunneling mechanism, doping Li + in VO x improved the efficiency of hole injection and balanced carriers by adjusting the work function , thereby improving the efficiency of the device. The experimental results indicated that Li-doped VO x film prepared by solution processing is a very potential material as the HIL of high-performance OLED.
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Dazhao Wang,Jianbei Qiu,Dacheng Zhou,Songhan Hu,Yugeng Wen,Ke Zhang,Qi Wang,Yong Yang,Hao Wu,Zhangwen Long,Xizheng Li,Jiacheng Pi,Enhao Cao
All-inorganic CsPbBr 3 nanocrystal (NC) has been extensively studied because of its excellent optical properties . However, its poor stability restricts further practical applications. Glass as a carrier can solve this problem well while still maintaining excellent luminescent properties. The traditional CsPbBr 3 NC glass is obtained by melt-quenching and heat treatment. In this paper, we first propose LiBr-induced the self-crystallization of CsPbBr 3 NC in borosilicate glass without heat treatment. We demonstrated that the lithium changes the glass network structure, resulting in a higher aggregation state in the glass. At the same time, the lithium doping increases the degree of phase separation of the glass. Both of these two factors benefit the formation of the CsPbBr 3 NC. The self-crystallized CsPBbr 3 NC glass has better luminescent properties than NC glass obtained by heat treatment. What is more, the self-crystallized CsPbBr 3 NC glass shows good environmental and water stability, especially thermal stability. We combined blue and red phosphors to construct a white light-emitting diode (WLED), which has excellent application prospects. Our work paves a new path for the research of perovskite nanocrystals, and provides promising development for future optoelectronic applications.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 25
·7976-7981
·
IF 7.393
Xiankai Fu,Wanqi Chen,Xiaowen Hao,Zhimin Zhang,Ruolan Tang,Bo Yang,Xiang Zhao,Liang Zuo
This paper reports a new candidate material λ-Ti3O5 for microwave absorption. λ-Ti3O5 has been proposed to be metastable and has emerged at room temperature only in the form of nanocrystals. To prepare high purity λ-Ti3O5, the formation energies of 27 different elements doped into λ-Ti3O5 were calculated by first-principles from the energy point of view. It was found that Li has the strongest stabilizing effect on λ-Ti3O5. The prepared λ-Ti3O5 and Li/λ-Ti3O5 show good microwave absorption properties: the efficient absorption bandwidth of λ-Ti3O5 can reach 7.9 GHz at 1.7 mm thickness, and the efficient absorption bandwidth of Li/λ-Ti3O5 can reach 7.4 GHz at 1.2 mm thickness. In addition, we propose a strategy of using the number of states of the micro-electric field to predict the microwave absorption properties of materials, which is helpful to the understanding of the origin and development of microwave absorption.
研究领域:
材料科学
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物理学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）