The incubation layers in microcrystalline silicon films （μc-Si：H） are studied in detail. The incubation layers in μc- Si：H films are investigated by biracial Raman spectra, and the results indicate that either d...
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The incubation layers in microcrystalline silicon films （μc-Si：H） are studied in detail. The incubation layers in μc- Si：H films are investigated by biracial Raman spectra, and the results indicate that either decreasing silane concentration （SC） or increasing plasma power can reduce the thickness of incubation layer. The analysis of the in-situ diagnosis by plasma optical emission spectrum （OES） shows that the emission intensities of the SiH＊（412 nm） and Hα （656 nm） lines are time-dependent, thus SiH＊/Hα ratio is of temporal evolution. The variation of SiH＊/Hα ratio can indicate the variation in relative concentration of precursor and atomic hydrogen in the plasma. And the atomic hydrogen plays a crucial role in the formation of μc-Si：H; thus, with the plasma excited, the temporal-evolution SiH＊/Hα ratio has a great influence on the formation of an incubation layer in the initial growth stage. The fact that decreasing the SC or increasing the plasma power can decrease the SIH＊/Hα ratio is used to explain why the thickness of incubation layer can reduce with decreasing the SC or increasing the plasma power.
Indium-tin oxide (ITO) that has unique characteristics of good conductivity and high light transmission over the visible spectrum is widely used as the transparent conducting electrode to solar cells and optoelectroni...
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Indium-tin oxide (ITO) that has unique characteristics of good conductivity and high light transmission over the visible spectrum is widely used as the transparent conducting electrode to solar cells and optoelectronicdevices. The indium tin oxide (ITO) films have been prepared on glass substrates by reactive evaporation of In-Sn alloy in a system with an oxygen pressure of 1.4 × 10-1 Pa and a substrate temperature of 160°C. In this research, the deposition rate is in the range from 0.1 to 0. 6 A·sec-1. The electrical resistivity of ITO films is in the range from 1.7 × 10-4 to 4.2 × 10-3 Ω·cm. The carrier concentration is between 1.3 × 1020 and 1.91 × 1021 cm-3, and the hall mobility is between 10.7 and 28.9 cm2v-1 s-1. The influence of deposition rate on structural, optical and electrical properties of the obtained films has been investigated.
A high gain cascade connected preamplifier for optical receivers is developed with 0.5 μm GaAs PHEMT technology from the Nanjing Electronic devices Institute. To begin with, the transimpedance amplifier has a -3 dB b...
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A high gain cascade connected preamplifier for optical receivers is developed with 0.5 μm GaAs PHEMT technology from the Nanjing Electronic devices Institute. To begin with, the transimpedance amplifier has a -3 dB bandwidth of 10 GHz, with a small signal gain of around 9 dB. The post-stage distributed amplifier (DA) has a -3 dB bandwidth of close to 20 GHz, with a small signal gain of around 12 dB. As a whole, the cascade preamplifier has a measured small signal gain of 21.3 dB and a transimpedance of 55.3 dBΩ in a 50 n system. With a higher signal-to-noise ratio than that of the TIA and a markedly improved waveform distortion compared with that of the DA, the measured output eye diagram for 10 Gb/s NRZ pseudorandom binary sequence is clear and symmetric.
A single power supply common-gate (CG) current mode transimpedance preamplifier (TIA) is developed with a 0.5 μm GaAs PHEMT process. The amplifier has a measured -3 dB bandwidth of 7.5 GHz and a transimpedance gain o...
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A single power supply common-gate (CG) current mode transimpedance preamplifier (TIA) is developed with a 0.5 μm GaAs PHEMT process. The amplifier has a measured -3 dB bandwidth of 7.5 GHz and a transimpedance gain of 45 dBΩ. Both the input and output voltage standing wave ratios (VSWR) are less than 2 within the bandwidth. The equivalent input noise current spectral density varies from 14.3 to 22 pA/√Hz, with an average value of 17.2 pA/√Hz. Having a timing jitter of 14 ps and eye amplitude of about 138 mV, the measured output eye diagram for 10 Gb/s NRZ pseudorandom binary sequence (PRBS) is clear and satisfactory.
Two silole monomers 1-methyl-1-phenyl-3,4-diphenyl-2,5-bis(4'-bromophenyl)silole and 1-methyl-1-phenyl-3,4-diphenyl-2,5-bis(5'-bromo-2'-thienyl)silole with a phenyl substitution on the silicon atom were su...
Two silole monomers 1-methyl-1-phenyl-3,4-diphenyl-2,5-bis(4'-bromophenyl)silole and 1-methyl-1-phenyl-3,4-diphenyl-2,5-bis(5'-bromo-2'-thienyl)silole with a phenyl substitution on the silicon atom were successfully prepared via one-pot synthesis routes with methyl-phenyl-bis(phenylethynyl)silane as the starting *** series of random and alternating silole-containing polyfluorenes were synthesized by incorporating the two siloles individually in Suziki coupling reactions,from which their performances in polymeric light-emitting diodes that show green-and red-light emissions were *** extemal quantum efficiencies of 1.2 and 1.8% were achieved from the green-and red-light emissions,***-light electroluminescence (EL) with relatively balanced simultaneous red,green,and blue emissions were demonstrated by incorporation of the two siloles directly conjugated on the blue-emissive polyfluorene *** white-light EL device displays maximum luminous efficiency of 2.01 cdA-1 for a brightness of 338 cd/m2 and the device also holds a luminous efficiency of 1.86 cd/A for a higher brightness of 2703 cd/*** device shows stable CIE coordinates of (0.33,0.36).
A series of copolymers PFSO based on 2,8-dibenzothiopene-S,S-dioxide and 3,6-fluorene were synthesized via the Suzuki *** incorporation of 2,8-dibenzothiopene-S,S-dioxide into the polyfluorene main chain not only supp...
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A series of copolymers PFSO based on 2,8-dibenzothiopene-S,S-dioxide and 3,6-fluorene were synthesized via the Suzuki *** incorporation of 2,8-dibenzothiopene-S,S-dioxide into the polyfluorene main chain not only suppressed the long-wavelength emission but significantly improved color purity of the copolymer-based *** (EA) spectroscopy is an attractive nonlinear optical technique which allows experimental estimate of the susceptibility of transition dipole moment to an electric field,the change in polarizability,and the magnitude of the change in permanent electric dipole *** use EA spectroscopy to investigate the electronic structure of the copolymers and the effect of Beta phase formation on the electronic structures of PFSO.
作者：
Lei WangYan ZhouJian PeiYong CaoJian WangInstitute of Polymer Optoelectronic Material and Devices
Key Laborotory of Functional Materials of Ministry of Education South China University of Technology Guangzhou 510640 P.R.China The Key Laboratory of Bioorganic Chemistry and Molecular Engineering and the Key Laboratory of Polymer Chemistry and Physics of Ministry of Education College of Chemistry and Molecular Engineering Peking University Beijing 100871 P.R.China
We demonstrate the preparation of composite photovoltaic devices by using the blends of multi-armed CdS nanorods with conjugated polymer, poly[2-methoxy-5-（2＇-ethylhexyloxy）-1,4-phenylenevinylene] （MEH-PPV）. Mult...
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We demonstrate the preparation of composite photovoltaic devices by using the blends of multi-armed CdS nanorods with conjugated polymer, poly[2-methoxy-5-（2＇-ethylhexyloxy）-1,4-phenylenevinylene] （MEH-PPV）. Multi-armed CdS nanorods are prepared by thermolysing single precursor cadmium ethylxanthate [Cd（exan）2] in pure hexadecylamine solution under ambient conditions. The photoluminescence of MEH-PPV can be effectively quenched in the composites at high CdS nanocrystal （nc-CdS）//MEH-PPV ratios. Post-treatment of the multi-armed CdS nanorods by refluxing in pyridine significantly increases the performance of the composite photovoltaic devices. Power conversion efficiency is obtained to be 0.17% under AM 1.5 illumination for this composite device.
A pure conducting polymer （PANI-CSA） film conditioned by an electric discharge was tentatively utilized as an cathode for emitting electrons under electric fields. The emission of electrons was observed using a phos...
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A pure conducting polymer （PANI-CSA） film conditioned by an electric discharge was tentatively utilized as an cathode for emitting electrons under electric fields. The emission of electrons was observed using a phosphor （ZnO：Zn） screen excited by electrons from the conditioned film. The film morphology was investigated using a scanning electron microscope and it was found that undulate whisker-like sites formed on the surface. The emission was presumably due to the undulate whisker-like sites. The field enhancement factor was estimated to be as high as 1150. The electron emitting process of the PANI-CSA film conditioned by electric discharge was also discussed.
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