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排序方式: 共有546条查询结果,搜索用时 15 毫秒
61.
朱煜 《中国锅炉压力容器安全》2008,(7):63-66
根据现场检修情况及日常超温统计,提出超临界锅炉高再管氧化皮脱落的原因。从检修及运行两方面采取措施,防止高再管的超温,及因氧化皮脱落引起的爆管。 相似文献
62.
HT7610A/B和HT7611A/BPIR控制器是台湾HOLTEK公司生产的新型控制器件 ,该器件主要用于自动照明和安全报警系统。文中介绍了HT7610A/B与HT7611A/BPIR控制器的功能、特点及两种应用电路。 相似文献
63.
DTMF芯片HT9170在数据通信中的应用 总被引:3,自引:0,他引:3
双音多频(DTMF)技术是在电话机中实现电话号码快速传输的一种可靠技术,它以其很强的抗干扰能力和较高的传输速度广泛用于电话通信系统和数据通信系统。文中介绍了DTMF的技术原理和HOLTEK公司生产的DTMF芯片HT9170的结构功能,给出了它们在数字通信中的应用电路和具体的系统框图。 相似文献
64.
《Microelectronics Reliability》2014,54(12):2766-2774
In this study, the gold/poly(3-hexylthiophene):[6,6]-phenyl C61 butyric acid methyl ester/n-type silicon (Au/P3HT:PCBM/n-Si) metal–polymer–semiconductor (MPS) Schottky barrier diodes (SBDs) were investigated in terms of the effects of PCBM concentration on the electrical parameters. The forward and reverse bias current–voltage (I–V) characteristics of the Au/P3HT:PCBM/n-Si MPS SBDs fabricated by using the different P3HT:PCBM mass ratios were studied in the dark, at room temperature. The main electrical parameters, such as ideality factor (n), barrier height (ΦB0), series resistance (Rs), shunt resistance (Rsh), and density of interface states (Nss) were determined from I–V characteristics for the different P3HT:PCBM mass ratios (2:1, 6:1 and 10:1) used diodes. The values of n, Rs, ΦB0, and Nss were reduced, while the carrier mobility and current were increased, by increasing the PCBM concentration in the P3HT:PCBM organic blend layer. The ideal values of electrical parameters were obtained for 2:1 P3HT:PCBM mass ratio used diode. This shows that the electrical properties of MPS diodes strongly depend on the PCBM concentration of the P3HT:PCBM organic layer. Moreover, increasing the PCBM concentration in P3HT:PCBM organic blend layer improves the quality of the Au/P3HT:PCBM/n-Si (MPS) SBDs which enables the fabrication of high-quality electronic and optoelectronic devices. 相似文献
65.
The effects of metal chlorides such as LiCl, NaCl, CdCl2 and CuCl2 on optical transmittance, electrical conductivity as well as morphology of PEDOT:PSS films have been investigated. Transmittance spectra of spun PEDOT:PSS layers were improved by more than 6% to a maximum of 94% in LiCl doped PEDOT:PSS film. The surface of the PEDOT:PSS films has exhibited higher roughness associated with an increase in the electrical conductivity after doping with metal salts. The improvement in the physical properties of PEDOT:PSS as the hole transport layer proved to be key factors towards enhancing the P3HT:PCBM bulk heterojunction (BHJ) solar cells. These improvements include significantly improved power conversion efficiency with values as high as 6.82% associated with high fill factor (61%) and larger short circuit current density (∼18 mA cm−2). 相似文献
66.
Enhanced Vertical Charge Transport in a Semiconducting P3HT Thin Film on Single Layer Graphene 下载免费PDF全文
Vasyl Skrypnychuk Nicolas Boulanger Victor Yu Michael Hilke Stefan C. B. Mannsfeld Michael F. Toney David R. Barbero 《Advanced functional materials》2015,25(5):664-670
The crystallization and electrical characterization of the semiconducting polymer poly(3‐hexylthiophene) (P3HT) on a single layer graphene sheet is reported. Grazing incidence X‐ray diffraction revealed that P3HT crystallizes with a mixture of face‐on and edge‐on lamellar orientations on graphene compared to mainly edge‐on on a silicon substrate. Moreover, whereas ultrathin (10 nm) P3HT films form well oriented face‐on and edge‐on lamellae, thicker (50 nm) films form a mosaic of lamellae oriented at different angles from the graphene substrate. This mosaic of crystallites with π–π stacking oriented homogeneously at various angles inside the film favors the creation of a continuous pathway of interconnected crystallites, and results in a strong enhancement in vertical charge transport and charge carrier mobility in the thicker P3HT film. These results provide a better understanding of polythiophene crystallization on graphene, and should help the design of more efficient graphene based organic devices by control of the crystallinity of the semiconducting film. 相似文献
67.
《International Journal of Hydrogen Energy》2020,45(58):33111-33127
A numerical method was developed for optimising solar–hydrogen energy system to supply renewable energy for typical household connected with the grid. The considered case study involved household located in Diyala Governorate, Iraq. The solar–hydrogen energy system was designed to meet the desired electrical load and increase the renewable energy fraction using optimum fuel cell capacity. The simulation process was conducted by MATLAB based on the experimental data for electrical load, solar radiation and ambient temperature at a 1-min time-step resolution. Results demonstrated that the optimum fuel cell capacity was approximately 2.25 kW at 1.8 kW photovoltaic power system based on the average of the daily energy consumption of 6.8 kWh. The yearly renewable energy fraction increased from 31.82% to 95.82% due to the integration of the photovoltaic system with a 2.25 kW fuel cell used as a robust energy storage unit. In addition, the energy supply, which is the economic aspect for the optimum system, levelised electricity cost by approximately $0.195/kWh. The obtained results showed that the proposed numerical analysis methodology offers a distinctive property that can be used effectively to optimise hybrid renewable energy systems. 相似文献
68.
Jong Bok Kim Ze-Lei Guan Stephanie Lee Eleni Pavlopoulou Michael F. Toney Antoine Kahn Yueh-Lin Loo 《Organic Electronics》2011,12(11):1963-1972
Contrary to polymer solar cells with bulk-heterojunction active layers, devices with planar-heterojunction active layers allow the decoupling of active layer phase separation from constituent crystallization, and their relative influence on device performance. We fabricated planar-heterojunction devices by first processing the electron donor and electron acceptor in isolation; they were subsequently laminated across the donor–acceptor interface to establish electrical contact. Thermal annealing was intentionally avoided after lamination to maintain the pristine charge transfer interface. Lamination thus obviates the need for solvent orthogonality; more importantly, it provides independent process tuning of individual organic semiconductor layers, ultimately allowing control over constituent structural development. We found the short-circuit current density of planar-heterojunction solar cells comprising poly(3-hexyl thiophene), P3HT, and [6,6]-phenyl-C61-butyric acid methyl ester, PCBM, as the electron donor and acceptor, respectively, to be generally independent of the annealing history of P3HT. On the contrary, thermal annealing PCBM prior to lamination mainly led to a reduction in short-circuit current density. This deterioration is correlated with the development of preferentially oriented PCBM crystals that hinders electron transport in the vertical direction. 相似文献
69.
Claudio Girotto Davide Moia Barry P. Rand Paul Heremans 《Advanced functional materials》2011,21(1):2-2
In this study, we report high performance organic solar cells with spray coated hole‐transport and active layers. With optimized ink formulations we are able to deposit films with controlled thickness and very low surface roughness (<10 nm). Specifically we deposit smooth and uniform 40 nm thick films of poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as well as films composed of a mixture of poly(3‐hexyl thiophene) (P3HT) and the C60‐derivative (6,6)‐phenyl C61‐butyric acid methyl ester (PCBM) with thicknesses in the range 200–250 nm. To control film morphology, formation and thickness, the optimized inks incorporate two solvent systems in order to take advantage of surface tension gradients to create Marangoni flows that enhance the coverage of the substrate and reduce the roughness of the film. Notably, we achieve fill factors above 70% and attribute the improvement to an enhanced P3HT crystallization, which upon optimized post‐drying thermal annealing results in a favorable morphology. As a result, we could extend the thickness of the layer to several hundreds of nanometers without noticing a substantial decrease of the transport properties of the layer. By proper understanding of the spreading and drying dynamics of the inks we achieve spray coated devices with power conversion efficiency of 3.75%, with fill factor, short circuit current and open circuit voltage of 70%, 9.8 mA cm?2 and 550 mV, respectively. 相似文献
70.
Anthony J. Morfa Alexandre M. Nardes Sean E. Shaheen Nikos Kopidakis Jao van de Lagemaat 《Advanced functional materials》2011,21(13):2580-2586
The charge‐collection dynamics in poly(3‐hexylthiophene:[6,6]‐phenyl‐C61‐butyric acid methyl ester (P3HT:PCBM) bulk heterojunctions are studied in thick (>1 μm) devices using time‐of‐flight measurements and external quantum‐efficiency measurements. The devices show Schottky‐diode behavior with a large field‐free region in the device. Consequently, electron transport occurs by diffusion in the bulk of the active layer. At high applied biases where the depletion region spans the entire active layer, normal time‐of‐flight transients are observed from which the electron mobility can be determined. Here, the electron mobility follows Poole–Frenkel behavior as a function of field. At lower applied biases, where the depletion region only spans a small portion of the active layer, due to a high density of dark holes, the recombination kinetics follow a first‐order rate law with a rate constant about two orders of magnitude lower than that predicted by Langevin recombination. 相似文献