Carbon-based CsPbI perovskite solar cells without hole transporter (C-PSCs) have achieved intense attention due to its simple device structure and high chemical stability. However, the severe interface energy loss at the CsPbI/carbon interface, attributed to the lower hole selectivity for inefficient charge separation, greatly limits device performance. Hence, dipole electric field (DEF) is deployed at the above interface to address the above issue by using a pole molecule, 4-trifluoromethyl-Phenylammonium iodide (CF-PAI), in which the ─NH group anchors on the perovskite surface and the ─CF group extends away from it and connects with carbon electrode.
View Article and Find Full Text PDFWide-bandgap perovskites are promising absorbers for state-of-the-art tandem solar cells to feasibly surpass Shockley-Queisser limit with low cost. However, the commonly used mixed halide perovskites suffer from poor stability; particularly, photoinduced phase segregation. Electrospray deposition is developed to bridge the gap of growth rate between iodide and bromide components during film growth by spatially confining the anion diffusion and eliminating the kinetic difference, which universally improves the initial homogeneity of perovskite films regardless of device architectures.
View Article and Find Full Text PDFOrganic host-guest doped materials exhibiting the room temperature phosphorescence (RTP) phenomenon have attracted considerable attention. However, it is still challenging to investigate their corresponding luminescence mechanism, because for host-guest systems, it is very difficult to obtain single crystals compared to single-component or co-crystal component materials. Herein, we developed a series of organic doped materials with triphenylamine (TPA) as the host and TPA derivatives with different electron-donating groups as guests.
View Article and Find Full Text PDFIEEE/ACM Trans Comput Biol Bioinform
December 2021
Recently, coronary heart disease has attracted more and more attention, where segmentation and analysis for vascular lumen contour are helpful for treatment. And intravascular optical coherence tomography (IVOCT) images are used to display lumen shapes in clinic. Thus, an automatic segmentation method for IVOCT lumen contour is necessary to reduce the doctors' workload while ensuring diagnostic accuracy.
View Article and Find Full Text PDFRecent research has reported the application of image fusion technologies in medical images in a wide range of aspects, such as in the diagnosis of brain diseases, the detection of glioma and the diagnosis of Alzheimer's disease. In our study, a new fusion method based on the combination of the shuffled frog leaping algorithm (SFLA) and the pulse coupled neural network (PCNN) is proposed for the fusion of SPECT and CT images to improve the quality of fused brain images. First, the intensity-hue-saturation (IHS) of a SPECT and CT image are decomposed using a non-subsampled contourlet transform (NSCT) independently, where both low-frequency and high-frequency images, using NSCT, are obtained.
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