- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Understanding the Impact of Cu-In-Ga-S Nanoparticles Compactness on Holes Transfer of Perovskite Solar Cells
摘要： Although a compact holes-transport-layer (HTL) ?lm has always been deemed mandatory for perovskite solar cells (PSCs), the impact their compactness on the device performance has rarely been studied in detail. In this work, based on a device structure of FTO/CIGS/perovskite/PCBM/ZrAcac/Ag, that effect was systematically investigated with respect to device performance along with photo-physics characterization tools. Depending on spin-coating speed, the grain size and coverage ratio of those CIGS ?lms on FTO substrates can be tuned, and this can result in different hole transfer ef?ciencies at the anode interface. At a speed of 4000 r.p.m., the band level offset between the perovskite and CIGS modi?ed FTO was reduced to a minimum of 0.02 eV, leading to the best device performance, with conversion ef?ciency of 15.16% and open-circuit voltage of 1.04 V, along with the suppression of hysteresis. We believe that the balance of grain size and coverage ratio of CIGS interlayers can be tuned to an optimal point in the competition between carrier transport and recombination at the interface based on the proposed mechanism. This paper de?nitely deepens our understanding of the hole transfer mechanism at the interface of PSC devices, and facilitates future design of high-performance devices.
关键词： perovskite solar cells,compactness,Cu-In-Ga-S,hole transfer,holes transport layer,recombination
更新于2025-11-21 10:59:37
-
Design of Microstrip Bandpass Filters Based on Stair-Step Patch Resonator
摘要： In this research article, single pole bandpass filter using stair-step patch topology based on symmetrical and asymmetrical step impedance resonators has been designed for industrial, scientific and medical (ISM) band application. This filter has been modeled by Microwave Office simulator using RT/Duroid substrate constant of 10.8, the substrate thickness of 1.27mm, loss tangent of 0.0023 and copper metallization thickness of 0.035 mm. To enhance the stopband levels of filter response, two microstrip bandpass filters have been designed as two-pole configurations based on edge, and cross-coupled stair-step patch resonators using the same simulator tool and substrate specifications. The proposed filters have compact sizes of (0.311λ(cid:2917)(cid:2925) x 0.233λ(cid:2917)(cid:2925)) for single pole filter, (0.578λ(cid:2917)(cid:2925) x 0.24λ(cid:2917)(cid:2925) )for two-pole edge coupled filter and (0.566λ(cid:2917)(cid:2925) x 0.234λ(cid:2917)(cid:2925))for two-pole cross-coupled filter designed at center frequencies of 2.4, 2.46 and 2.41 GHz respectively. These filters have interesting insertion loss and return loss magnitudes, narrow band frequency responses, second harmonic suppression and good stopband levels. Apart from ISM band applications, the proposed filters can be adopted in WLAN systems and Bluetooth applications for short range devices. The experimental results for designed filters are of good consistency with the simulations.
关键词： ISM band applications,stair-step patch resonator,filter compactness,narrow band frequency response,Microstrip bandpass filters,second harmonic frequency blocking
更新于2025-09-23 15:21:21
-
Algorithms for 3D Particles Characterization Using X-Ray Microtomography in Proppant Crush Test
摘要： We present image processing algorithms for a new technique of ceramic proppant crush resistance characterization. To obtain the images of the proppant material before and after the test we used X-ray microtomography. We propose a watershed-based unsupervised algorithm for segmentation of proppant particles, as well as a set of parameters for the characterization of 3D particle size, shape, and porosity. An effective approach based on central geometric moments is described. The approach is used for calculation of particles’ form factor, compactness, equivalent ellipsoid axes lengths, and lengths of projections to these axes. Obtained grain size distribution and crush resistance ?t the results of conventional test measured by sieves. However, our technique has a remarkable advantage over traditional laboratory method since it allows to trace the destruction at the level of individual particles and their fragments; it grants to analyze morphological features of ?nes. We also provide an example describing how the approach can be used for veri?cation of statistical hypotheses about the correlation between particles’ parameters and their crushing under load.
关键词： shape factor,axes of equivalent ellipsoid,geometric moments,watershed,invariants,matching of particles,unsupervised segmentation,compactness,porosity
更新于2025-09-23 15:21:21
-
[IEEE 2018 25th IEEE International Conference on Image Processing (ICIP) - Athens (2018.10.7-2018.10.10)] 2018 25th IEEE International Conference on Image Processing (ICIP) - Evaluation on the Compactness of Supervoxels
摘要： Supervoxels are perceptually meaningful atomic spatio-temporal regions in videos, which has great potential to reduce the computational complexity of downstream video applications. Many methods have been proposed for generating supervoxels. To effectively evaluate these methods, a novel supervoxel library and benchmark called LIBSVX with seven collected metrics was recently established. In this paper, we propose a new compactness metric which measures the shape regularity of supervoxels and is served as a necessary complement to the existing metrics. To demonstrate its necessity, we first explore the relations between the new metric and existing ones. Correlation analysis shows that the new metric has a weak correlation with (i.e., nearly independent of) existing metrics, and so reflects a new characteristic of supervoxel quality. Second, we investigate two real-world video applications. Experimental results show that the new metric can effectively predict some important application performance, while most existing metrics cannot do so.
关键词： metric evaluation,Supervoxel,video segmentation,compactness
更新于2025-09-19 17:15:36
-
Spurious harmonic suppression in compact coupled-line bandpass filter with asymmetric perturbations
摘要： Present article exhibits the design of a third-order compact parallel-coupled line bandpass filter at 5.25 GHz having asymmetric perturbations to suppress the second harmonic. Initially, the effects of compactness on filter characteristics have been studied by synthesising the distributed filter network into its equivalent circuit model. The design has been initiated by computing the unit cell model, which leads to the first-order and third-order design instances with an improvement in compactness over the traditional parallel-coupled line filter. In contrary, compactness in the filter characteristics degrades the second harmonic level subject to enhanced imbalances among the odd- and even-mode velocities at the coupled lines. Subsequently, the improvement in the harmonic suppression of 53 dB and 58 dB has been achieved by incorporating different non-uniform perturbations to the outer and coupled edges of the compact filters. Accordingly, compactness of 58% and 71% have been obtained subject to the folded and in-line designs over the conventional layout.
关键词： harmonic suppression,compactness,Bandpass filter,parallel-coupled lines,perturbations
更新于2025-09-16 10:30:52