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Micro-Nanostructures|8 Article(s)
Research on the impact of spin coating silver nano clusters on the performance of OLED devices
Jun-tao HU, Qing-qing WEI, Jie LI, Kai XU, and Xiang-hua WANG
To achieve uniform distribution of silver nano clusters (SNCs) on substrate and reveal its effect on the performance of organic light-emitting diode (OLED), the SNCs incorporated OLED was fabricated and SNCs were coated by mul-ti-step spin coating. Compared with the device without SNCs film, the brightness and current efficiency of the OLED devices with SNCs film were highly raised. The enhancement is attributed to SNCs induced local surface plasmon (LSP) oscillation, which can increase the radiative rate of excitons on Alq3 molecules. To achieve uniform distribution of silver nano clusters (SNCs) on substrate and reveal its effect on the performance of organic light-emitting diode (OLED), the SNCs incorporated OLED was fabricated and SNCs were coated by mul-ti-step spin coating. Compared with the device without SNCs film, the brightness and current efficiency of the OLED devices with SNCs film were highly raised. The enhancement is attributed to SNCs induced local surface plasmon (LSP) oscillation, which can increase the radiative rate of excitons on Alq3 molecules.
Optoelectronics Letters
- Publication Date: Jan. 01, 2018
- Vol. 14, Issue 5, 321 (2018)
Research on the preparation and growth mechanism of ZnO micro/nano nails
Yu-jie LI, and Hai-ming ZHANG
High quality zinc oxide (ZnO) micro/nano nails were prepared through thermal evaporation on the Si (100) substrate. Scanning electron microscopy (SEM) image shows that the bottom of the nanometer nails present hexagonal structure. The tip diameter of the micro/nano nails is about 319.9 nm, and the length is over 20 μm. X-ray crystal diffraction (XRD) pattern shows that the sample has a hexagonal wurtzite structure and preferred orientation in (002) direction obviously. Photoluminescence (PL) spectrum shows a strong ultraviolet (UV) luminescence peak near the wavelength of 346 nm. Finally, the growth mechanism of the ZnO micro/nano nails is analyzed and studied. High quality zinc oxide (ZnO) micro/nano nails were prepared through thermal evaporation on the Si (100) substrate. Scanning electron microscopy (SEM) image shows that the bottom of the nanometer nails present hexagonal structure. The tip diameter of the micro/nano nails is about 319.9 nm, and the length is over 20 μm. X-ray crystal diffraction (XRD) pattern shows that the sample has a hexagonal wurtzite structure and preferred orientation in (002) direction obviously. Photoluminescence (PL) spectrum shows a strong ultraviolet (UV) luminescence peak near the wavelength of 346 nm. Finally, the growth mechanism of the ZnO micro/nano nails is analyzed and studied.
Optoelectronics Letters
- Publication Date: Jan. 01, 2018
- Vol. 14, Issue 4, 248 (2018)
Electrospun zinc oxide nanospheres for ultrasensitive room-temperature gas sensors
Fu-ru ZHONG, Yong-cai ZHANG, Lin-lin WANG, and Jie ZHOU
Zinc oxide (ZnO) nanospheres with excellent sensing ability towards formaldehyde were successfully synthesized us-ing a single-capillary electrospinning method. Structural and electrical characteristics of the as-synthesized ZnO nan-ospheres were systematically investigated. The scanning electron microscope (SEM) images clearly display a novel structure of ZnO with pores distributed on the surface of the nanospheres. The results demonstrate that the ZnO nano-spheres possess excellent formaldehyde gas-sensing properties. At room temperature, the response of ZnO nano-spheres to formaldehyde with concentration of 100 ppm is determined to be 126.3. In addition, the ZnO nanosphere sensors exhibit short response time of 30 s and short recovery time of 2 s. These excellent gas-sensing properties make the ZnO nanospheres a promising material for the application in environmental monitoring devices. Zinc oxide (ZnO) nanospheres with excellent sensing ability towards formaldehyde were successfully synthesized us-ing a single-capillary electrospinning method. Structural and electrical characteristics of the as-synthesized ZnO nan-ospheres were systematically investigated. The scanning electron microscope (SEM) images clearly display a novel structure of ZnO with pores distributed on the surface of the nanospheres. The results demonstrate that the ZnO nano-spheres possess excellent formaldehyde gas-sensing properties. At room temperature, the response of ZnO nano-spheres to formaldehyde with concentration of 100 ppm is determined to be 126.3. In addition, the ZnO nanosphere sensors exhibit short response time of 30 s and short recovery time of 2 s. These excellent gas-sensing properties make the ZnO nanospheres a promising material for the application in environmental monitoring devices.
Optoelectronics Letters
- Publication Date: Jan. 01, 2018
- Vol. 14, Issue 4, 245 (2018)
Sol-gel synthesis of black ZnO/AuNPs nanocomposites for effective photocatalytic activity of methylene blue
Hong-yan ZHANG, Shu-guo YU, and Ming-jing BIAN
In this study, we present a facile method for the fabrication of ZnO/AuNPs hexagonal wurtzite structure by sol-gel method. Transmission electron microscope (TEM) results indicate that the synthesized AuNPs have good round shape and uniform size with an average diameter of 15 nm. Scanning electron microscope (SEM) results show that the pre-pared ZnO/AuNPs nanocomposites are uniform spheroidal nanoparticles with sizes in diameter from 60 nm to 100 nm. The presence of Zn, Au and O elements in those samples is determined by X-ray photoelectron spectroscopy (XPS) analysis. The investigation of photocatalytic ability shows that the ZnO/AuNPs (8 mL) achieve complete degradation of methylene blue (MB) under UV irradiation with 65 min. We can conclude that the presence of AuNPs hybrid ZnO can strongly enhance the photocatalytic performance of MB compared to pure ZnO, which may be attributed to the larger specific surface area and surface plasmon resonance (SPR) effect of AuNPs hybrid ZnO nanocomposites. This method may provide a new way to improve ZnO photocatalysis for water cleaning application. In this study, we present a facile method for the fabrication of ZnO/AuNPs hexagonal wurtzite structure by sol-gel method. Transmission electron microscope (TEM) results indicate that the synthesized AuNPs have good round shape and uniform size with an average diameter of 15 nm. Scanning electron microscope (SEM) results show that the pre-pared ZnO/AuNPs nanocomposites are uniform spheroidal nanoparticles with sizes in diameter from 60 nm to 100 nm. The presence of Zn, Au and O elements in those samples is determined by X-ray photoelectron spectroscopy (XPS) analysis. The investigation of photocatalytic ability shows that the ZnO/AuNPs (8 mL) achieve complete degradation of methylene blue (MB) under UV irradiation with 65 min. We can conclude that the presence of AuNPs hybrid ZnO can strongly enhance the photocatalytic performance of MB compared to pure ZnO, which may be attributed to the larger specific surface area and surface plasmon resonance (SPR) effect of AuNPs hybrid ZnO nanocomposites. This method may provide a new way to improve ZnO photocatalysis for water cleaning application.
Optoelectronics Letters
- Publication Date: Jan. 01, 2018
- Vol. 14, Issue 4, 241 (2018)
A 45-channel 100 GHz AWG based on Si nanowire waveguides
Kai-li LI, Jia-shun ZHANG, Jun-ming AN, Jian-guang LI, Liang-liang WANG, Yue WANG, Yuan-da WU, Xiao-jie YIN, and Xiong-wei and HU
A 45-channel 100 GHz arrayed waveguide grating (AWG) based on Si nanowire waveguides is designed, simulated and fabricated. Transfer function method is used in the spectrum simulation. The simulated results show that the central wavelength and channel spacing are 1 562.1 nm and 0.8 nm, respectively, which are in accord with the designed values, and the crosstalk is about -23 dB. The device is fabricated on silicon-on-insulator (SOI) substrate by deep ultraviolet lithography (DUV) and inductively coupled plasma (ICP) etching technologies. The 45-channel 100 GHz AWG exhibits insertion loss of 6.5 dB and crosstalk of -8 dB. A 45-channel 100 GHz arrayed waveguide grating (AWG) based on Si nanowire waveguides is designed, simulated and fabricated. Transfer function method is used in the spectrum simulation. The simulated results show that the central wavelength and channel spacing are 1 562.1 nm and 0.8 nm, respectively, which are in accord with the designed values, and the crosstalk is about -23 dB. The device is fabricated on silicon-on-insulator (SOI) substrate by deep ultraviolet lithography (DUV) and inductively coupled plasma (ICP) etching technologies. The 45-channel 100 GHz AWG exhibits insertion loss of 6.5 dB and crosstalk of -8 dB.
Optoelectronics Letters
- Publication Date: Jan. 01, 2018
- Vol. 14, Issue 3, 161 (2018)
Investigation on refractive index sensing of single silver nanoparticle at tightly focused light illumination
Si SHEN, Xiang-hui WANG, Jing-wei SUN, Fei FAN, and Sheng-jiang and CHANG
Based on thegeneralized Mie theory, refractive index sensing characteristics of single silver nanoparticle respectively illuminated by tightly focused linearly-polarized and radially-polarized light beams are investigated. The spectra for localized surface plasmon resonances (LSPR) under different dielectric environments demonstrate that distinct dipolar and quadrupolar resonances can be always observed for the case of radial polarization, while there is only strong dipolar resonance for the case of linear polarization. The dipolar mode has a higher sensitivity. However, the figure of merit (FOM) for the quadrupolar resonance is much higher than that for the dipolar resonance, because the quadrupolar resonance has a narrower width. Based on thegeneralized Mie theory, refractive index sensing characteristics of single silver nanoparticle respectively illuminated by tightly focused linearly-polarized and radially-polarized light beams are investigated. The spectra for localized surface plasmon resonances (LSPR) under different dielectric environments demonstrate that distinct dipolar and quadrupolar resonances can be always observed for the case of radial polarization, while there is only strong dipolar resonance for the case of linear polarization. The dipolar mode has a higher sensitivity. However, the figure of merit (FOM) for the quadrupolar resonance is much higher than that for the dipolar resonance, because the quadrupolar resonance has a narrower width.
Optoelectronics Letters
- Publication Date: Jan. 01, 2018
- Vol. 14, Issue 1, 5 (2018)
Enhancement of R6G fluorescence by N-type porous silicon deposited with gold nanoparticles
Jia-qing MO, Jing JIANG, Zhen-gang ZHAI, Fu-gui SHI, and Zhen-hong JIA
By the electrochemical anodization method, we achieve the single-layer macroporous silicon on the N-type silicon, and prepare gold nanoparticles with sodium citrate reduction method. Through injecting the gold nanoparticles into the porous silicon by immersion, the fluorescence quenching mechanism of porous silicon influenced by gold nanoparticles is analyzed. Then the macroporous silicon deposited with gold nanoparticles is utilized to enhance the fluorescence of rhodamine 6G (R6G). It is found that when the macroporous silicon is deposited with gold nanoparticles for 6 h, the maximum fluorescence enhancement of R6G (about ten times) can be realized. The N-type porous silicon deposited with gold nanoparticles can be an excellent substrate for fluorescence detection. By the electrochemical anodization method, we achieve the single-layer macroporous silicon on the N-type silicon, and prepare gold nanoparticles with sodium citrate reduction method. Through injecting the gold nanoparticles into the porous silicon by immersion, the fluorescence quenching mechanism of porous silicon influenced by gold nanoparticles is analyzed. Then the macroporous silicon deposited with gold nanoparticles is utilized to enhance the fluorescence of rhodamine 6G (R6G). It is found that when the macroporous silicon is deposited with gold nanoparticles for 6 h, the maximum fluorescence enhancement of R6G (about ten times) can be realized. The N-type porous silicon deposited with gold nanoparticles can be an excellent substrate for fluorescence detection.
Optoelectronics Letters
- Publication Date: Jan. 01, 2017
- Vol. 13, Issue 1, 10 (2017)
Microstructure and microwave absorption properties of MWCNTs reinforced magnesium matrix composites fabriccated by FSP
Yu-hua CHEN, Yu-qing MAO, Ji-lin XIE, Zi-lin ZHAN, and Liang YU
Multiwall carbon nanotubes (MWCNTs) reinforced magnesium matrix (MWCNTs/Mg) composites were successfully fabricated by friction stir processing (FSP). Microstructure and microwave-absorption properties of WCNTs/Mg composites are studied. The results show that with increasing the MWCNTs content to 7.1% in volume fraction, the agglomeration of MWCNTs is found in the WCNTs/Mg composites. The addition of MWCNTs has little effect on microwave-absorption properties. With increasing the frequency from 2 GHz to 18 GHz, the microwave absorption of the composites decreases. Compared with the absorption loss of the MWCNTs, the reflection loss of base material takes the most part of the loss of the microwave, and the increase of the reflection loss can promote electromagnetic shielding properties of the composites. Moreover, the electromagnetic shielding properties of the composites are less than ?85 dB in the lower frequency range from 0.1 MHz to 3 GHz. With increasing the content of MWCNTs, the electrical conductivity of the composites is decreased, and the electromagnetic shielding properties is slightly enhanced. Multiwall carbon nanotubes (MWCNTs) reinforced magnesium matrix (MWCNTs/Mg) composites were successfully fabricated by friction stir processing (FSP). Microstructure and microwave-absorption properties of WCNTs/Mg composites are studied. The results show that with increasing the MWCNTs content to 7.1% in volume fraction, the agglomeration of MWCNTs is found in the WCNTs/Mg composites. The addition of MWCNTs has little effect on microwave-absorption properties. With increasing the frequency from 2 GHz to 18 GHz, the microwave absorption of the composites decreases. Compared with the absorption loss of the MWCNTs, the reflection loss of base material takes the most part of the loss of the microwave, and the increase of the reflection loss can promote electromagnetic shielding properties of the composites. Moreover, the electromagnetic shielding properties of the composites are less than ?85 dB in the lower frequency range from 0.1 MHz to 3 GHz. With increasing the content of MWCNTs, the electrical conductivity of the composites is decreased, and the electromagnetic shielding properties is slightly enhanced.
Optoelectronics Letters
- Publication Date: Jan. 01, 2017
- Vol. 13, Issue 1, 1 (2017)
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