JOURNAL OF MATERIALS CHEMISTRY
·
2012
·Vol. 22
·期 12
·5523-5530
·
IF 5.968
Wei Zhong,Fan Li,Lie Chen,Yiwang Chen,Yen Wei
Pristine and aligned electrospun fibers of poly[2-methoxy-5-(2′-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) have been fabricated by electrospinning. The key to success was using a binary solvent system, in which a poor solvent was introduced to increase interchain interactions of MEH-PPV. At the same time, the poor solvent should have a low surface tension and high conductivity. The emission spectra of pristine MEH-PPV in electrospun fibers, spin coating film and dilute solution were acquired and analyzed. The emission anisotropy of aligned electrospun fibers was investigated by polarized emission measurement. For pristine MEH-PPV fibers, the emission anisotropy is 0.47 at emission peak, indicating alignment of MEH-PPV chains along the electrospun fiber axis. For MEH-PPV/poly (ε-caprolactone) (PCL) electrospun fibers, the interchain energy transfer in MEH-PPV was significantly depressed. As a result, MEH-PPV/PCL electrospun fibers exhibited a strong blue shift of emission maximum and increased emission anisotropy of 0.66 compared with pristine MEH-PPV electrospun fibers. The ease of electrospinning of pristine MEH-PPV provides new opportunities for its application in unique optoelectronic devices.
研究领域:
材料科学
·
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
JOURNAL OF MODERN OPTICS
·
2014
·
IF 1.166
Cheng Qian,Enze Xu,Ning Sui,Yinghui Wang,Honglin Wu,Yunfei Song,Zhihui Kang,Hanzhuang Zhang
The photoluminescence (PL) characteristics of MEH-PPV hybrid films blended with Au nanoparticles are studied in detail. Due to the strong coupling effect between the surface plasmon of Au nanoparticles and the emission of MEH-PPV, the introduction of Au nanoparticles could enhance the PL intensity and modulate the shape of absorption and excitation spectra, according to our steady spectroscopy experiments. Besides, the relaxation dynamic experiments show that the non-radiative rate in the hybrid system decreases. The temperature and the excitation intensity (EI)-dependent PL spectral data indicate that hybrid MEH-PPV films have lower activation energy and higher thermal exchange rate. As a result, the thermal accumulation effect and the non-linearity of EI-induced PL enhancement are suppressed in hybrid films.
✓ 已验证
DOI
高影响因子
IEEE SENSORS JOURNAL
·
2025
·
IF 4.5
Shihan Su,Jia Zhou,Yexiong Huang,Wen Li,Changhai Zhu,Jie Yang,Xiaowei Zhang,Jiangshan Chen,Mingyu Pi,Mingdong Yi,Dingke Zhang
Photoelectric memristors, with the advantages of low-power consumption, high scalability and high parallelism, have provided a way for broadening the application of memristors. Photoelectric memristors based on heterojunction structures have gained high-performance in simulating biological synaptic plasticity and visual synaptic bionics. However, the effective separation and migration process of photo-generated carriers and the carrier dynamics mechanism is still the key factor and urgently need development. In this study, we proposed an optoelectronic memristor based on the MEH-PPV/C60 heterostructure to simulate neural synaptic functions. Compared with the monolayer structure, the heterojunction devices exhibited an improvement in both optical and electrical performance. Various synaptic behaviors were successfully emulated under light and electric stimulation signals. The photo-luminescence (PL), time-resolved PL (TRPL) and transient absorption (TA) spectra measurements were utilized to analyze and reveal the carrier transport mechanisms of MEH-PPV/C60 heterojunction. Due to the effective electron-hole separation by the built-in electric field at the heterojunction interface, the memristor based on MEH-PPV/C60 heterojunction exhibited superior electrical and optical performance. A 3 × 4 memristor array was constructed to simulate the human visual system to perceive and remember images and an artificial visual system with fear sensing capability was presented, which achieved four key features of human visual fear receptors (threshold, no-adaptation, sensitization and relaxation). This work provides strategies for the development of future memristor structures and the construction of human-like visual systems.
✓ 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）