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121.
In this paper, a spectrum-based wrinkling analysis method via two-dimensional Fourier transformation is proposed aiming to solve the difficulty of nanoscale wrinkle evaluation. It evaluates the wrinkle characteristics including wrinkling wavelength and direction simply using a single wrinkling image. Based on this method, the evaluation results of nanoscale wrinkle characteristics show agreement with the open experimental results within an error of 6%. It is also verified to be appropriate for the macro wrinkle evaluation without scale limitations. The spectrum-based wrinkling analysis is an effective method for nanoscale evaluation, which contributes to reveal the mechanism of nanoscale wrinkling. 相似文献
122.
Santolo Daliento Vincenzo d'Alessandro Pierluigi Guerriero Orlando Tari 《Progress in Photovoltaics: Research and Applications》2015,23(2):194-200
In this paper, the selective illumination approach is adopted to separately extract the shunt resistance of the individual subcells belonging to a tandem cell. The method relies on simple theoretical considerations and is based on the measurement of the current–voltage characteristic of the tandem cell by alternately keeping one of the subcells under dark conditions. Numerical simulations are employed to support the reliability of the technique, which is experimentally tested on micromorph devices deposited onto glass covered by a V‐shaped transparent conducting oxide and subject to different thermal treatments. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
123.
Helmut Mckel Gabriel Micard Kenneth Varner 《Progress in Photovoltaics: Research and Applications》2015,23(2):135-149
A theoretical analysis of the power loss and series resistance of the front side emitter in silicon solar cells is presented. Existing 1D models (infinitely long finger) and 2D models (including the effect of busbars) of emitter series resistance contribution are extended to the case of selective emitters. The general case of different current densities for both emitters in the selective emitter scheme is considered in these extensions. The resulting models depend on the individual sheet resistances and current densities in both emitters and the device's overall grid geometry. The models are corroborated by finite element simulation of the potential in the emitter. An excellent agreement is found between the analytical models, and the simulations for a wide range of sheet resistances typically encountered in silicon solar cells. Grid simulations using the 2D model are applied to solar cells with selective emitters, where the width of the low‐resistive emitter was varied. The simulations demonstrate that the 2D model can explain the absolute change in fill factor observed in these cells. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
124.
P. Espinet‐Gonzlez C. Algora N. Núez V. Orlando M. Vzquez J. Bautista K. Araki 《Progress in Photovoltaics: Research and Applications》2015,23(5):559-569
A temperature accelerated life test on commercial concentrator lattice‐matched GaInP/GaInAs/Ge triple‐junction solar cells has been carried out. The acceleration of the aging has been accomplished by subjecting the solar cells at temperatures markedly higher than the nominal working temperature inside a concentrator, and the nominal photo‐current condition (820 X) has been emulated by injecting current in darkness. Three tests at different temperatures have been carried out. The failure distributions across the three test temperatures have been fitted to an Arrhenius–Weibull model. An Arrhenius activation energy of 1.59 eV was determined from the fit. The reliability functions and parameters of these solar cells at two nominal working conditions (80 and 100 °C) have been obtained. In both cases, the instantaneous failure rate function monotonically increases, that is, the failures are of the wear‐out kind. We have also observed that the reliability data are very sensitive to the nominal temperature condition. In fact, at a nominal working condition of 820 X and 80 °C, assuming that the concentration module works 5 h per day, the warranty time obtained for a failure population of 5% has been 113 years. However, for a nominal working condition of 820 X and 100 °C, the warranty time obtained for a failure population of 5% has been 7 years. Therefore, in order to offer a long‐term warranty, the working temperature could be a key factor in the design of the concentration photovoltaic systems. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
125.
Dong‐Won Lee Won‐Ju Cho Jun‐Kwang Song Oh‐Yun Kwon Won‐Hee Lee Chi‐Hong Park Kyung‐Eun Park Heesoo Lee Yong‐Nam Kim 《Progress in Photovoltaics: Research and Applications》2015,23(7):829-837
High‐temperature‐induced and humidity‐induced degradation behaviors were investigated through the failure analysis of encapsulated Cu(In,Ga)Se2 (CIGS) modules and non‐encapsulated CIGS cells. After being exposed to high temperature (85 °C) for 1000 h, the efficiency loss of CIGS modules and the resistivities of the aluminum‐doped zinc oxide (AZO) layer, CIGS layer, and Mo layer were slightly increased. After damp heat (DH) testing (85 °C/85% RH), the efficiency of some modules decreased significantly accompanied by discoloration, and in these areas, the resistivity of the AZO layers increased markedly. The causes of degradation of CIGS cells after high temperature and DH tests were suggested through X‐ray photoelectron spectroscopy analysis. The high‐temperature‐induced degradation behaviors were revealed to be increases in series resistance of the CIGS cells, due to the adsorption of oxygen on the AZO, CIGS, and Mo layers. The degradation behavior after DH (85 °C/85% RH) exposure was caused by the adsorption of oxygen, as well as the generation of Zn(OH)2 due to water molecules. In particular, the humidity‐induced degradation behavior in discolored CIGS modules was ascribed to the generation of Zn(OH)2 and carboxylic acids in the AZO layer, due to a chemical reaction between the AZO, ethylene‐vinyl acetate copolymer, and water. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
126.
R. Timmreck K. Leo M. Riede 《Progress in Photovoltaics: Research and Applications》2015,23(10):1353-1356
Recently organic tandem solar cells with record efficiency had been shown comprising identical absorber materials in both subcells. Such structures pose new challenges for characterization. The standard test methods for measuring spectral response of tandem solar cells can not be applied. The standard procedures demand for different bias illumination during measuring spectral response allowing to select the subcell being current limiting. With subcells comprising identical absorber materials, thus having identical absorption spectra, such a selection is not trivial. In this paper, we show that with the help of detailed optical simulations of such tandem organic solar cells, their characterization is possible, and we apply the proposed method to a sample structure. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
127.
Yan Guan Dayu Zhou Jin Xu Xiaohua Liu Fei Cao Xianlin Dong Johannes Müller Tony Schenk Uwe Schroeder 《固体物理学:研究快报》2015,9(10):589-593
A wealth of studies have confirmed that the low‐field hysteresis behaviour of ferroelectric bulk ceramics and thin films can be described using Rayleigh relations, and irreversible domain wall motion across the array of pining defects has been commonly accepted as the underlying micro‐mechanism. Recently, HfO2 thin films incorporated with various dopants were reported to show pronounced ferroelectricity, however, their microscopic domain structure remains unclear till now. In this work, the effects of the applied electric field amplitude, frequency and temperature on the sub‐coercive polarization reversal properties were investigated for 10 nm thick Si‐doped HfO2 thin films. The applicability of the Rayleigh law to ultra‐thin ferroelectric films was first confirmed, indicating the existence of a multi‐domain structure. Since the grain size is about 20–30 nm, a direct observation of domain walls within the grains is rather challenging and this indirect method is a feasible approach to resolve the domain structure. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
128.
Rouholah Ashiri 《哲学杂志》2015,95(1):1-11
The great sensitivity of titanium alkoxides to hydrolysis makes their sol–gel transformation very fast and thus difficult to control. A method was proposed to alleviate this drawback. Preparation of highly transparent solutions and nanothin films is another objective of the present research. Employing nanoemulsion method and optimizing the processing conditions, a clear solution of well-dispersed nanosized particles was obtained. With the proposed process BaTiO3 precursor sols and nanothin films with enhanced optical transparency towards the visible were prepared. The optimal formulation of the sol consists of acetic acid, barium acetate, 2-propanol, TTIP and deionized water with 6:1:1:1:150 M ratios, respectively. It was found that the reduction of the temperature in the initial stage of mixing of precursors controls the size of the forming species and accordingly improves the stability and transparency of the sol. The results also showed that the applied modifications and optimizations significantly downsize the particles within the sol to the nanometric scale and accordingly result in a significant improvement in the optical response of the products. 相似文献
129.
《Current Applied Physics》2015,15(12):1580-1586
The characteristics of gasification reactions for carbon–carbonate mixtures were experimentally investigated at high temperatures up to 900 °C, considering the application of the mixtures to the external anode media of a direct carbon fuel cell. A thermo-gravimetric analysis (TGA) was conducted in either a nitrogen or carbon dioxide ambient environment for Li2CO3, K2CO3 and a mixture of these two substances with carbon black. Changes in the exit gas composition were also monitored during the heating process. It was shown that gasification in the mixture media occurs much more rapidly than carbonate decomposition at elevated temperatures, even for low concentrations of CO2. It was also shown that the loading of carbonates to carbon significantly affects the global gasification reaction; it increased the reaction rate by an order of magnitude and decreased its activation energy. Based on the experimental observations, a simplified reaction model of gasification was suggested for the anode media of a DCFC, regarding carbonate-catalysed and metal-catalysed pathways of Boudouard reactions. 相似文献
130.
Saengrawee Sriwichai Sumarin Niroj Sukon Phanichphant 《Molecular Crystals and Liquid Crystals》2015,621(1):142-149
The electropolymerized poly(3-aminobenzoic acid) (PABA) film on indium tin oxide electrode was used for fabrication of cytochrome c (Cyt c) modified PABA thin film upon immobilization of Cyt c onto the PABA surface. The obtained Cyt c modified PABA thin film was characterized by UV-vis spectroscopy, XPS, AFM, and SEM-EDX techniques. Shifts of the UV-vis absorption peaks were observed from Cyt c modified PABA thin film compared with Cyt c solution and PABA thin film. The formation of the covalent amide bond between the carboxylic groups of PABA and amine groups in Cyt c was observed from XPS results. 相似文献