JOURNAL OF NANOPARTICLE RESEARCH
·
2013
·Vol. 15
·期 9
·1-7
·
IF 2.175
Zong Kai,Lu SiHeng,Wang Hao,Sun YuXiu,Liu JingBing,Yan Hui
Cu 2 ZnSnSe 4 quantum dots (QDs) with controllable sizes have been synthesized via a hot-injection method. The diameters of the QDs range from 3.2 to 10.1 nm with the tunable band gap from 1.27 to 1.54 eV by adjusting the reaction temperatures from 180 to 240 °C. Structural and Raman scattering data confirm that Cu 2 ZnSnSe 4 is obtained without other secondary phases. The band gaps of the QDs with diameters less than 4.6 nm show an obvious blue shift to higher energy due to quantum confinement effect. It indicates that the Cu 2 ZnSnSe 4 QDs can be a potential candidate for quantum-dot-sensitized solar cells in the future.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Chinese Physics B
·
2023
·Vol. 32
·期 1
·017901
·
IF 1.7
Siwen You,Ziyi Shao,Xiao Guo,Junjie Jiang,Jinxin Liu,Kai Wang,Mingjun Li,Fangping Ouyang,Chuyun Deng,Fei Song,Jiatao Sun,Han Huang
Hybrid organic–inorganic perovskite thin films have attracted much attention in optoelectronic and information fields because of their intriguing properties. Due to quantum confinement effects, ultrathin films in nm scale usually show special properties. Here, we report on the growth of methylammonium lead iodide (MAPbI3) ultrathin films via co-deposition of PbI2 and CH3NH3I (MAI) on chemical-vapor-deposition-grown monolayer MoS2 as well as the corresponding photoluminescence (PL) properties at different growing stages. Atomic force microscopy and scanning electron microscopy measurements reveal the MoS2 tuned growth of MAPbI3 in a Stranski–Krastanov mode. PL and Kelvin probe force microscopy results confirm that MAPbI3/MoS2 heterostructures have a type-II energy level alignment at the interface. Temperaturedependent PL measurements on layered MAPbI3 (at the initial stage) and on MAPbI3 crystals in averaged size of 500 nm (at the later stage) show rather different temperature dependence as well as the phase transitions from tetragonal to orthorhombic at 120 and 150 K, respectively. Our findings are useful in fabricating MAPbI3/transition-metal dichalcogenide based innovative devices for wider optoelectronic applications.
研究领域:
材料科学
·
光学
·
物理化学
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 7
·1607
·
IF 3.1
Hang Li,Jiazhen He,Xiaoqian Wang,Qi Liu,Xuemin Luo,Mingwei Wang,Jinfeng Liu,Chengqi Liu,Yong Liu
As a direct band gap semiconductor, perovskite has the advantages of high carrier mobility, long charge diffusion distance, high defect tolerance and low-cost solution preparation technology. Compared with traditional metal halide perovskites, which regulate energy band and luminescence by changing halogen, perovskite quantum dots (QDs) have a surface effect and quantum confinement effect. Based on the LaMer nucleation growth theory, we have synthesized CsPbBr3QDs with high dimensional homogeneity by creating an environment rich in Br−ions based on the general thermal injection method. Moreover, the size of the quantum dots can be adjusted by simply changing the reaction temperature and the concentration of Br−ions in the system, and the blue emission of strongly confined pure CsPbBr3perovskite is realized. Finally, optical and electrochemical tests suggested that the synthesized quantum dots have the potential to be used in the field of photocatalysis.
研究领域:
材料科学
·
光电催化
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2023
·Vol. 36
·期 4
·477-485
·
IF 1
He Ting,Dong Na,Yao Yi,Xu Faqiang
Although lead-based halide perovskites have promising applications in optoelectronic devices, these applications are limited by the toxicity of the materials. Therefore, it is necessary to develop lead-free all-inorganic substitute such as tin-based halide perovskites in spite of the enormous challenges in their controllable synthesis and stability. Here, we report the controlled growth of high quality CsSnBr 3 microcrystals on SiO 2 /Si substrates by chemical vapor deposition method. The as-prepared products pre-dominantly show the morphology of triangle star and nail-like rod and the structure of cubic phase. The control of nucleation density and size of CsSnBr 3 microcrystals has been realized by varying the growth temperature. The results of air-exposed samples explain the structural instability of the tin-based perovskites due to the production of SnO. The power and temperature dependent photoluminescence spectra reveal that CsSnBr 3 microcrystals with different morphologies possess different exciton binding energies and produce different photoexcitation species due to the quantum confinement effect that changes the electron-hole effect.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2018
·
IF 2.687
Liyun Lv,Jingjing Liu,Hong Wang
Ag 2 S hollow nanospheres were synthesized by reaction between silver dodecanoate and thiourea in the presence of polyvinyl pyrrolidone (PVP) at ambient temperature within 30 min. Characterization studies by X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM) and scanning electron microscopy (SEM) showed that the prepared product had a monoclinic structure and was composed of thin shell enwrapped hollow nanospheres. Their large band gap energy of 3.67 eV, remarkable blue shifts both in the ultraviolet-visible (UV–vis) absorption spectrum and the photoluminescence (PL) emission peak could be well explained by the thin shell caused quantum confinement effects.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 7
·2980-2985
·
IF 3.288
Zhen Li,Li Li,Huali Liu,Fei Li,Jiaqi Zhao,Yu Wang
Mn2+-doped CsPbBr3 nanocrystals (NCs) within MCM-41 mesophase silica have been prepared via a template-assisted strategy by using MCM-41 as the template. The template-synthesized CsPb1−xMnxBr3 NCs (x = 0–1) with the investigated perovskite compositions are luminescent with 465 nm pure blue light. The coprecipitation of bulk materials can be controlled by varying the amount of Mn2+ doping because the formation energy of CsPbBr3 NCs rises slightly on increasing the Mn2+ content and then decreases with the further increase in the Mn2+ content. Furthermore, they also exhibit excellent UV and air stability due to the existence of MCM-41 mesoporous silica and can be used as phosphors for solid-state lighting.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTENGCOMM
·
2018
·Vol. 20
·期 46
·7473-7478
·
IF 3.304
Linyuan Lian,Guangmei Zhai,Feng Cheng,Yong Xia,Moyan Zheng,Jiangping Ke,Mingyang Gao,Huan Liu,Daoli Zhang,Luying Li,Jianbo Gao,Jiang Tang,Jianbing Zhang
Lead halide two-dimensional (2D) nanoplatelets (NPLs) have attracted intense interest due to their unique optoelectronic properties. However, environmental friendly lead-free 2D perovskite NPLs are highly desirable in terms of application. Herein, all-inorganic Cs3Bi2Br9 perovskite NPLs are synthesized for the first time via the hot injection method. The Cs3Bi2Br9 NPLs are parallelogram-shaped and exhibit an extremely sharp first exciton peak which blue-shifts substantially with respect to their bulk bandgap. The formation of Cs3Bi2Br9 NPLs is determined by the layered feature of Cs3Bi2Br9 crystalline structure and the shape of parallelogram is the reflection of the trigonal nature of Cs3Bi2Br9 crystal. The large blue-shift and extremely sharp first exciton peak are due to large exciton binding energy and quantum confinement in the Cs3Bi2Br9 NPLs and large exciton binding energy in Cs3Bi2Br9 crystal. The Cs3Bi2Br9 NPLs grow anisotropically from monodispersed parallelogram-shaped nuclei via Ostwald ripening, demonstrated by ex situ TEM investigation. Anion-exchange was used to effectively adjust the composition of the Cs3Bi2Br9 NPLs. Additionally, the Cs3Bi2Br9 NPLs exhibit excellent stability to air and illumination due to the robust crystal, BiOBr passivation and oleylamine and oleic acid co-passivation.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2018
·
IF 9.89
Jinyuan Zhao,Sunan Cao,Zhi Li,Nan Ma
Metal halide perovskites (MHPs) have recently attracted considerable attentions due to their remarkable optoelectronic properties. Colloidal synthesis of MHPs provides a versatile route to precisely control their dimensionality and the related optoelectronic properties. Herein, we report on amino acid (Trp)-mediated synthesis of quasi-two-dimensional CsPbBr3 perovskite nanoplatelets (NPLs) with well-controlled and tunable thickness. The number of layers (n) could be finely tuned from 4 to 12 by simply adjusting Trp concentration, leading to gradual red shift of their photoluminescence (PL). This allows us to directly correlate their thickness with the band gap energy in the quantum confinement regime, which is in good agreement with theoretical model. We found that Trp is the only hydrophobic amino acid to promote the formation of 2D CsPbBr3 NPLs. The use of Trp derivatives for CsPbBr3 nanocrystal synthesis indicates that the carboxyl group, amine group, and indole ring of Trp act synergistically on CsPbBr3 NPL formation.
研究领域:
材料科学
·
光学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2023
·Vol. 11
·期 11
·3805-3811
·
IF 6.4
Zaichun Sun,Yihao Wang,Bingchu Mei
Bismuth oxyhalides have attracted much attention in the field of optoelectronics because of their highly anisotropic crystal structure, tunable optical properties, and low toxicity. Few studies on the epitaxial growth of bismuth oxyhalides have been reported so far, however epitaxial thin films are suitable for investigating intrinsic properties and achieving device construction. In this study, we achieved the high quality epitaxial growth of BiOI thin film with thickness on the nanometer scale controllable via the deposition time. The bandgap of the BiOI exhibited a negative corelation with the film thickness owing to the quantum confinement effect. The as-fabricated photodetector based on the optimized thickness of the BiOI film exhibited high optoelectrical performance with a responsivity of 43.5 mA W−1 and normalized detectivity of 8.7 × 1010 Jones under the illumination of 405 nm laser. Furthermore, the photoresponse mechanism of the BiOI photodetector was tuned from a photoconduction to photogating effect depending on the thickness of the epitaxial thin film. The high crystallinity and continuous surface morphology contribute to the generation of the photogating effect of the BiOI film. This study enriches the investigation of bismuth oxyhalides and paves the way towards the design of efficient bismuth-based semiconductor optoelectronic devices.
研究领域:
材料科学
·
光电材料
·
半导体物理
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 13
·135701
·
IF 3.874
Aiqing Zhao,Yuhang Sheng,Cihui Liu,Songyan Yuan,Xiaoli Shan,Yunsong Di,Zhixing Gan
During synthesis, device processes, and applications of perovskite nanocrystals (NCs), there are usually inevitable interactions between perovskite NCs and polar solvents. To elaborately control the properties of perovskite NCs, investigating the effects of solvent polarity on perovskite NCs is thus highly important. Herein, fluorescent variations induced by different solvents into CsPbBr3 NCs solution are systematically studied. In this report, it is found that when CsPbBr3 NCs are treated with polar solvents, the fluorescence intensity decreases with a general redshift of fluorescence peak position. Moreover, the fluorescence quenching and peak position shift amplitude monotonously increase with the solvent polarity. Absorption spectra and fluorescent lifetime suggest that, with addition of polar solvents, the surface of NCs are destroyed and defect states are generated, leading to the fluorescent variations. Besides, dielectric constant of the solvent also increases with polarity, which may weaken the quantum confinement effect and decrease the exciton binding energy. We find the fluorescence may slightly blue shift if the emission of free carrier is strong enough with certain solvents, such as dimethylsulfoxide (DMSO). We also find the fluorescence intensity generally deceases to a stable state in 2 min, indicating quick interactions between CsPbBr3 NCs and solvents. However, water continuously quenches the fluorescence of CsPbBr3 NCs up to 72 h due to the poor miscibility between water and n-hexane. This work not only provides a comprehensive understanding on the fluorescent dynamics of CsPbBr3 NCs in polar solvents but also affords a potential fluorescent indicator for solvent polarity.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
ACS Applied Nano Materials
·
2023
·
IF 5.9
Zhongjie Cui,Shuaitao Qin,Haiyang He,Zhuoqi Wen,Dan Yang,Zhiyan Piao,Shiliang Mei,Wanlu Zhang,Ruiqian Guo
As a kind of luminescent nanomaterial, InP quantum dots (QDs) have been regarded as one of the most potential nontoxic alternatives for cadmium-based QDs in the light-emitting devices, and much progress has been obtained recently. However, their growth kinetics remains not fully revealed yet, and the effects of the shelling process on as-synthesized InP cores have been rarely investigated. Herein, the growth kinetics of InP QDs is investigated via the convenient method of varying halide ions, and their sequential growth is proposed according to the discontinuous evolution of their first exciton absorption peaks, especially the observed typical positions, which is different from the reported continuous evolution previously and means that the specific sized InP cores appeared during the growth stage. Moreover, the impacts of ZnS are analyzed from the quantum confinement effect of ZnS on InP cores with different sizes and interfacial heterovalent bonds. The coordination between these two aspects decides the final positions of the first exciton absorption peaks of InP/ZnS QDs. Compared with the positions of the first exciton absorption peaks of bare InP QDs, insufficient confinement of the ZnS shell to small InP cores causes the red-shift, but the heterovalent bonds at the interface cause the blue-shift. Furthermore, the emissions of final InP/ZnS QDs are influenced, and the emission from 484 to 578 nm is obtained via this facile synthetic protocol. It is thought that this study can reveal the growth of InP QDs and provide guidance to design rational InP-based QDs with desired emission and high performance, contributing to the fabrication of efficient light-emitting devices.
研究领域:
材料科学
·
纳米技术
·
光学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2022
·
IF 4.931
Shuangshuang Liu,Jiaojiao Wang,Lele Wang,Xianlin Wang,Xinhui Zhou,Jin Wang
Polarized fluorescent polymers can be promisingly used for many applications. In this work, the polarized fluorescent poly[2-methoxy,5-(2′-ethylhexyloxy)-1,4-phenylene vinylene]@MOF (MEH-PPV@MOF) composites were synthesized via the direct chain-introduction method. Firstly, long-range ordered porous metal-organic framework (MOF) crystals were synthesized. Through morphology observation and X-ray diffraction measurement, the water stability, thermal stability and structural stability of synthesized MOF were analyzed, to determine the preservation treatment of the material and the process parameters of introducing polymer chains in the subsequent experiment. Then, the MEH-PPV chains were directly introduced into the MOF channels via a solution-mediated incorporation approach. The measurement results of powder X-ray diffraction, nitrogen adsorption and Fourier transform infrared spectroscopy showed that the MEH-PPV chains were successfully introduced into the MOF channels. Finally, the fluorescent properties of the MEH-PPV@MOF composites were characterized via the photoluminescence spectroscopy. It was found that the accommodation of MEH-PPV chains within 1-D channels of MOF led to a strong blue-shift of the photoluminescence spectrum, due to the quantum confinement effect. Also, the polarization ratio calculated from the polarization luminescence spectra of the composites was 2.215. This indicates that the MEH-PPV@MOF composites prepared by the direct chain-introduction method with the help of the solution-mediated approach have good photoluminescence anisotropy.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）