Enhanced efficiency of crystalline Si solar cells based on kerfless-thin wafers with nanohole arrays

Several techniques have been proposed for kerfless wafering of thin Si wafers, which is one of the most essential techniques for reducing Si material loss in conventional wafering methods to lower cell cost. Proton induced exfoliation is one of promising kerfless techniques due to the simplicity of the process of implantation and cleaving. However, for application to high efficiency solar cells, it is necessary to cope with some problems such as implantation damage removal and texturing of (111) oriented wafers. This study analyzes the end-of-range defects at both kerfless and donor wafers and ion cutting sites. Thermal treatment and isotropic etching processes allow nearly complete removal of implantation damages in the cleaved-thin wafers. Combining laser interference lithography and a reactive ion etch process, a facile nanoscale texturing process for the kerfless thin wafers of a (111) crystal orientation has been developed. We demonstrate that the introduction of nanohole array textures with an optimal design and complete damage removal lead to an improved efficiency of 15.2% based on the kerfless wafer of a 48 mu m thickness using the standard architecture of the Al back surface field

Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC

Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe

Phenomenological understanding of dewetting and embedding of noble metal nanoparticles in thin films induced by ion irradiation

The present experimental work provides the phenomenological approach to understand the dewetting in thin noble metal films with subsequent formation of nanoparticles (NPs) and embedding of NPs induced by ion irradiation. Au/polyethyleneterepthlate (PET) bilayers were irradiated with 150 keV Ar ions at varying fluences and were studied using scanning electron microscopy (SEM) and cross-sectional transmission electron microscopy (X-TEM). Thin Au film begins to dewet from the substrate after irradiation and subsequent irradiation results in spherical nanoparticles on the surface that at a fluence of 5 × 1016 ions/cm2 become embedded into the substrate. In addition to dewetting in thin films, synthesis and embedding of metal NPs by ion irradiation, the present article explores fundamental thermodynamic principles that govern these events systematically under the effect of irradiation. The results are explained on the basis of ion induced sputtering, thermal spike inducing local melting and of thermodynamic driving forces by minimization of the system free energy where contributions of surface and interfacial energies are considered with subsequent ion induced viscous flow in substrate. © 2014 Elsevier B.V. All rights reserved.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

X-ray spectroscopy study of ZnxSn1-xO2 nanorods synthesized by hydrothermal technique

An environment friendly, inexpensive solvothermal route is used to synthesize polycrystalline ZnxSn1-xO2 (0.0 &lt;= x &lt;= 0.07) nanorods with nanoflower morphology without using any organic solvents, surfactant or any catalytic agent under low hydrothermal pressure. Scanning electron microscopy (SEM) equipped with energy-dispersive x-ray spectra depicts the formation of near stoichiometric ZnxSn1-xO2 nanorods. SEM analysis reveals that Zn incorporation in SnO2 decreases the nanorod diameter from similar to 20 nm to similar to 10 nm. High-resolution x-ray diffraction analysis reveals the rutile structure for x &lt;= 0.04 samples, while for x = 0.07 a Zn2SnO4 phase is observed. Near edge x-ray absorption fine structure and x-ray photoemission spectroscopy indicate that Zn atoms have been substituted for Sn sites in SnO2 lattice without forming secondary phases and also create numerous oxygen vacancy in the structure

Bright Nitrogen-Vacancy Centers in Diamond Inverted Nanocones

Quantum emitters with long-lived quantum memories are a promising scalable quantum system for repeater-based quantum communications, quantum sensing, and distributed quantum computing networks. Although color centers in solids have been successful, further improvements in the efficiency of optical control and detection and scalability are necessary for practical uses. Here, we demonstrate that single nitrogen-vacancy centers can be efficiently coupled in diamond inverted nanocones that can be fabricated directly on the high-quality CVD diamond surface by the alldirection diagonal dry etching using a solid cone-shaped Faraday cage. Since the inverted cone shape allows efficient photon collection thanks to the single-directional guiding of photons, we report 20-fold enhancement in the photon collection efficiency from a single emitter while preserving a long electron spin coherence time. Furthermore, we show that an inverted nanocone can be picked and placed on the target position with desiredorientation by using conventional microprobe tips. The demonstrated structure can also be applied to similar emitters in other solids; thus, it can be used for finding new possibilities for scalable photonic quantum devices

A Survey of Practice Patterns for Clinical Nodal Staging Prior to Neoadjuvant Chemotherapy in Breast Cancer

Background The importance of clinical staging in breast cancer has increased owing to the wide use of neoadjuvant systemic therapy (NST). This study aimed to investigate the current practice patterns regarding clinical nodal staging in breast cancer in real-world settings. Materials and Methods A web-based survey was administered to board-certified oncologists in Korea, including breast surgical, medical, and radiation oncologists, from January to April 2022. The survey included 19 general questions and 4 case-based questions. Results In total, 122 oncologists (45 radiation, 44 surgical, and 33 medical oncologists) completed the survey. Among them, 108 (88%) responded that clinical staging before NST was primarily performed by breast surgeons. All the respondents referred to imaging studies during nodal staging. Overall, 64 (52.5%) responders determined the stage strictly based on the radiology reports, whereas 58 (47.5%) made their own decision while noting radiology reports. Of those who made their own decisions, 88% referred to the number or size of the suspicious node. Of the 75 respondents involved in prescribing regimens for neoadjuvant chemotherapy, 58 (77.3%) responded that the reimbursement regulations in the selection of NST regimens affected nodal staging in clinical practice. In the case-based questions, high variability was observed among the clinicians in the same cases. Conclusions Diverse assessments by specialists owing to the lack of a clear, harmonized staging system for the clinical nodal staging of breast cancer can lead to diverse practice patterns. Thus, practical, harmonized, and objective methods for clinical nodal staging and for the outcomes of post-NST response are warranted for appropriate treatment decisions and accurate outcome evaluation. Nodal stage serves a pivotal role in making treatment decisions in breast cancer patients. This study investigated current practice patterns regarding clinical nodal staging in breast cancer in a real-world setting.N