NANOTECHNOLOGY
·
2020
·Vol. 32
·期 7
·075601
·
IF 3.551
Sijing Su,Jialin Shen,Haochen Sun,Jiaqi Tao,Da Xu,Tong Wei,Chao Fan,Ziying Wang,Chun Sun,Wengang Bi
The poor light absorption of visible light for Cs4PbBr6 nanocrystals (NCs) has severely impeded their practical applications. Although the semiconductor/perovskite heterostructure holds great promise for enhancement in absorption, it has remained a serious challenge for synthesizing a semiconductor/perovskite heterostructure. In this work, monodispersed Janus heterostructures composed of Cs4PbBr6 decorated with either multiple Ag or single Ag on its surface (named as mAg/Cs4PbBr6 and sAg/Cs4PbBr6 respectively), are successfully prepared. The size of Ag seeds has an important effect on the shape of the products. Small-sized Ag seeds lead to the formation of mAg/Cs4PbBr6 Janus NCs, while relatively large-sized Ag seeds produce sAg/Cs4PbBr6 Janus NCs. It is noted that this work not only provides a novel method for the modification of individual Cs4PbBr6 NCs, but also enhances the absorption of the Cs4PbBr6 in the visible region, indicating great potential for optoelectronic applications, such as photocatalysis and solar cells.
研究领域:
材料科学
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光学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2022
·Vol. 156
·期 23
·
IF 4.304
Pu Lei,Gu Yarong,Meng Qian,Pang Qi,Lu Aijiang,Zhao Lijuan
Zero-dimensional (0D) all-inorganic cesium lead halide perovskites, particularly Cs 4 PbBr 6 , have been attracting wide attention due to their excellent optical properties and stability. The research also focuses on the origin of green emission from Cs 4 PbBr 6 , which has a bandgap located in the ultraviolet B (UVB) region. So far, both Cs 4 PbBr 6 without visible emission and with green emission have been successfully prepared; however, the origin of green emission remains controversial. Photocurrent response is one of the effective approaches to explore how the photo-excited carriers influence the photo-physical properties of materials. In our study, Cs 4 PbBr 6 particles without visible emission and with green emission were synthesized and their photocurrent response was investigated. The former showed a positive photocurrent response, while the latter showed a negative photocurrent response. The negative response was believed to be due to a built-in electric field constructed by the charged excitons in green-emissive Cs 4 PbBr 6 . From our calculations, numerous vacancies of Br are easier to appear in green-emissive Cs 4 PbBr 6 lattices, which could combine the neutral excitons to form charged excitons. This work may contribute to the explanation of the origin of green emission of Cs 4 PbBr 6 to some extent.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yueli Liu,Hongbing Guo,Aohan Mei,Keqiang Chen,Wen Chen
Recently, all-inorganic halide perovskite materials have attracted much attention in the fields of humidity sensor due to their sensitive surface, tunable bandgap, high conductivity and excellent carrier mobility. However, their inherent instability and limited sensitivity restrict further application in electronic devices. Herein, we demonstrate a high-performance impedimetric humidity sensor based on an all-inorganic halide perovskite Cs 4 PbBr 6 nanocrystals (NCs), which are obtained by anti-solvent method without long chain ligands. It is found that V Br ∙ defects act as the active site to enhance the ability of adsorbing water molecules. The humidity sensor of Cs 4 PbBr 6 NCs achieves high response value over 4 orders of magnitude at 11–98 % relative humidity, short response/recovery time (8 s/6 s), favorable repeatability, excellent selectivity and good long-term stability. Moreover, high humidity sensing performance enables the humidity sensor of Cs 4 PbBr 6 NCs to possess great potentials in breath monitor and noncontact switch application.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Qi Wang,Wenzhi Wu,Ruirui Wu,Sen Yang,Yunxia Wang,Jixiang Wang,Zhijun Chai,Qiuju Han
Here, Cs 4 PbBr 6 microcrystals (MCs) are synthesized using a two-phase liquid-liquid immiscible method. In order to unravel the bright green photoluminescence (PL) mechanism for in-situ Cs 4 PbBr 6 MCs, the thermal stability of PL spectra for the supernatant and precipitate of reactants is investigated comparatively. Exciton binding energy, exciton-phonon (EP) coefficient and PL lifetime all indicate that the PL of the precipitate has similar temperature dependence as that of the supernatant. It is found that, according to its structural and optical characteristics , the supernatant of the reactants is CsPbBr 3 nanocrystals (NCs). We also find that the bright green PL from the precipitate of the reactants is due to CsPbBr 3 NCs embedded into Cs 4 PbBr 6 MCs. Experimental results further reveal the size of CsPbBr 3 NCs embedded into Cs 4 PbBr 6 MCs is larger than that of CsPbBr 3 NCs in the supernatant. The surface passivation of the composites can thus help to suppress the thermal quenching of PL for CsPbBr 3 NCs, which opens a new avenue for enhancing the thermal stability of PL for perovskite NCs.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Crystals
·
2021
·Vol. 11
·期 11
·1287
·
IF 2.589
Yue Han,Rong Wen,Feng Zhang,Linlin Shi,Wenyan Wang,Ting Ji,Guohui Li,Yuying Hao,Lin Feng,Yanxia Cui
High-quality, all-inorganic CsPbBr3/Cs4PbBr6composite perovskite nanocrystals (NCs) were obtained with all-solution-processing at room temperature, and a photodetector (PD) with high detectivity was realized based on CsPbBr3/Cs4PbBr6NCs. The detectivity (D*) of the proposed PD is 4.24 × 1012Jones under 532 nm illumination, which is among the highest levels for PDs based on all-inorganic perovskite NCs. In addition, a high linear dynamic range (LDR) of 115 dB under 1 V bias was also realized. Furthermore, the underlying mechanism for the enhanced performance of the proposed PD was discussed. Our work might promote the preparation of high-performance PDs based on dual-phase all-inorganic perovskite nanocrystals.Keywords:all-inorganic lead halide perovskite;CsPbBr3;Cs4PbBr6;perovskite nanocrystals;photodetector
研究领域:
材料科学
·
光电子学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2025
·
IF 5.1
Yichi Zhong,Jian Huang,Hongyu Yang,Zhanpeng Wang,Kun Qian,Jingzhou Li,Hongxing Dong,Long Zhang
All-inorganic cesium lead bromide zero-dimensional perovskite Cs4PbBr6 is highly valued for its excellent photoelectric conversion efficiency and exceptional stability. However, its application value in the visible light optical field is limited due to large bandgap and strong ionic and covalent bonds in the crystal structure, which inhibit photon emission in the visible light spectrum. Nonetheless the easily convertible properties among perovskite derivatives bring new opportunities. This study is the first to report the transformation of Cs4PbBr6 nanocrystals into CsPbBr3 nanocrystals, which then grow into nanowires and eventually form micrometer-scale optical microcavities. This innovative approach provides a novel strategy for the fabrication of perovskite micro-nano lasers and strengthens the connections among various perovskite derivatives. The nanowires exhibit excellent quantum size effects and are microdevices with polarized photoluminescence emission capability. Meanwhile, the large-sized microrods exhibit perfect lasing performance with low threshold ~34 μJ cm-2 and high Q-factor ~1229. These high-quality performances make Cs4PbBr6 nanocrystals have significant potential in diverse fields such as optical communication, biomedical applications, photonics and optoelectronics.
研究领域:
材料科学
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光学工程
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光电子学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2021
·Vol. 11
·期 27
·16453-16460
·
IF 3.361
Zikuan Shi,Yu Yang,Xin-Yuan Sun,Feng Lang,Liangwu Lin
We demonstrate the influence mechanism on the optical property of Cs4PbBr6 during purification of solution with different protonated levels and polarities. During the purification process, organic groups originating from oleic acid (OA) and PbBr impurity on the surface of Cs4PbBr6 nanocrystals can be removed using high polarity aprotic and protonic solvents, and the number of Br vacancies (VBr) can be reduced. The protonic polar solvent can not only etch the organic groups on the surface of nanocrystals, causing surface reconstruction and particle growth of nanocrystals, but also enter into the lattice of Cs4PbBr6 and react with the embedded CsPbBr3. However, aprotic polar solvent decreases the particle size of Cs4PbBr6 nanocrystals with the increase in the solvent polarity. The optical properties of Cs4PbBr6 can be effectively improved using aprotic polar solvents as a purification solvent, which is very significant to improve the luminescence efficiency of perovskites.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Physica Status Solidi-Rapid Research Letters
·
2021
·Vol. 15
·期 7
·2100169
·
IF 2.821
Tao Song,Bo Ma,Hao Wang,Xiao-Dong Zhang,Min Zhao,Pei-Zhu Zheng,Fei Gao,Qiang Wang,Hao-Li Zhang
One ancient recipe to produce rocky candies has found new applications in synthesizing Cs 4 PbBr 6 microcrystals, one 0D perovskite with [PbBr 6 ] 4− octahedra isolated by Cs + bridges that enable quantum confinement and high exciton binding energy favorable for photoluminescence (PL). Herein, various threads are used as seeds to grow perovskites microcrystals, in a way similar to rocky candy production recorded in ancient Chinese recipes. The Cs 4 PbBr 6 growth is an exothermic enthalpy driving process, with the surface energy differentiation determining the formation of rhombohedra shape. The synthesized Cs 4 PbBr 6 microcrystals show a large PL quantum yield (PLQY) of 31.5% and are used to fabricate white and green light-emitting diodes with high performance. Learning from history, this work provides one controllable and generally applicable avenue of fabricating high-quality perovskite crystals with promising applications in photonic and optoelectronic devices, and the elucidation of the growth mechanism offers useful guidance for critical factors directing crystal fabrications in future work.
研究领域:
材料科学
·
光学
·
光电设备
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Qingyun He,Enrou Mei,Xiaojuan Liang,Weidong Xiang
Here, polyvinyl butyral (PVB) films-protected CsPbBr 3 /Cs 4 PbBr 6 halide perovskite solids (HPSs) were successfully synthesized. The optical properties and structure of HPSs@PVB were studied, finding the photoluminescence quantum yields (PLQYs) of this novel composite material is as high as 60.4%. More importantly, HPSs@PVB has excellent thermal cyclability, water and ultraviolet (UV) resistance. In addition, HPSs@PVB was further applied to light emitting diodes (LEDs) and displays. By combining green-emitting HPSs@PVB and red-emitting CsPbBrI 2 NCs@PVB with InGaN 460 nm blue chip, white light emitting diode (WLED) device can be successfully fabricated. And the device exhibits good stability and the color gamut is as wide as 126%, reaching 94% of Rec. 2020. This work proposes a simple approach to solve the challenging stability issue of perovskite nanocrystals (NCs), having a positive implication for their practical application in LEDs and display backlights.
研究领域:
材料科学
·
光学工程
·
显示技术
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2021
·
IF 4.126
Xian Wu,Quan Zhou,Haodi Wu,Xinyuan Du,Guangda Niu,Guijie Liang,Qingsong Hu,Jiawen Xiao
There is a growing demand for novel scintillators with applications in security inspection, medical radiography, X-ray astronomy, and so on. However, the conventional all-inorganic scintillators encounter typical bottlenecks such as high cost, fixed emission band, and long decay time, etc. The recently developed halide perovskite scintillators are subjected to defects-induced thermal quenching and moisture instability. Herein, we developed a series of zero-dimensional perovskite single crystals (SCs) as scintillators with tunable emission through a simple low-temperature solution method. The emission wavelength of Cs4PbBr6–xClx SCs can be tuned from ∼528 to ∼433 nm by varying the Br/Cl ratio. In addition, the photoluminescent lifetimes can be shortened to 0.62 ns with the increase of Cl–. The scintillating properties of our SCs were studied, and the X-ray imaging results showed a high spatial resolution of 4.0 line-pairs per millimeter. Also, the obtained crystals exhibit impressive stability under ambient conditions. This work provides a new strategy to design and synthesize perovskite scintillators, which hold potential in promoting fast scintillators performance.
研究领域:
材料科学
·
光学
·
医学影像
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2022
·
IF 3.754
Chenfei Wang,Canyun Zhang,Fengchao Wang,Jin Chen,Enliang Ren,Jinfang Kong,Lan Li,Jiayue Xu,Yan Zhang
All-inorganic lead halide perovskite nanocrystals (NCs) have attracted enormous attention owing to their excellent optical properties such as ultrahigh photoluminescence quantum yield (PLQY), narrow full width at half maximum (FWHM) and broad emission spectra tunability. In this study, we reported the synthesis of colloidal perovskite NCs based on CsPbBr 3 @Cs 4 PbBr 6 composite structure. With the assistance of Tetraoctylammonium bromide (TOAB) ligands, the prepared CsPbBr 3 @Cs 4 PbBr 6 NCs show high PLQY of 94.7% and enhanced stability. The crystal morphology and phase structure of the CsPbBr 3 @Cs 4 PbBr 6 NCs were investigated by HRTEM and XRD measurements. In addition, the crystal morphology of CsPbBr 3 @Cs 4 PbBr 6 NCs presents cubic and circular particles with an average size of 9.3 nm. Compared with CsPbBr 3 NCs, the diphase CsPbBr 3 @Cs 4 PbBr 6 composite materials can perform higher optical properties due to the in-situ passivation of the generated Cs 4 PbBr 6 NCs. Furthermore, the fabricated LED device exhibits bright white light emission with a color coordinate of (0.335, 0.337), the corresponding color temperature of 5390 K and a color rendering index of 82.1 under the injection current of 30 mA. These results demonstrate that the obtained CsPbBr 3 @Cs 4 PbBr 6 NCs have a potential application in white light-emitting and display devices.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
Nanoscale
·
2018
·Vol. 11
·期 4
·1784-1789
·
IF 7.233
Qiang Jing,Yue Xu,Yucong Su,Xing Xing,Zhenda Lu
Cs4PbBr6 nanocrystals (NCs) have been recently studied as they can enhance the light emitting efficiency and stability of CsPbBr3 NCs. However, the synthesis of Cs4PbBr6 NCs is often accompanied by the generation of CsPbBr3 NCs, and less attention has been paid to how to exactly control their formation. Here, we investigated the key factors in deciding the final products in the hot-injection synthesis by a modified amine-free method. We found that the molarity ratio of Cs/Pb dominated the final products, while the amount of bromine had a relatively small effect. In addition, introducing a certain amount of oleylamine into the amine-free reaction leads to the formation of Cs4PbBr6, instead of CsPbBr3 NCs. This clearly shows that the protection ligand oleylamine also plays an important role in the formation of Cs4PbBr6 NCs. This well understood and fine control of the synthesis may inspire a new CsPbBr3@Cs4PbBr6 core–shell structure, with the same chemical elements but a different crystal phase in the core and the shell. This nanostructure would open a new avenue for enhancing the stability of perovskite nanocrystals.
研究领域:
材料科学
·
化学工程
✓ 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）