Optical Performance of Ag-based Back Reflectors with different Spacers in Thin Film Si Solar Cells

Abstract We have compared different Ag-based back reflectors (BRs) applied to superstrate-type microcrystalline Si devices grown on Asahi U glass. In particular, substitution of the conventional ZnO:Al layer by MgF 2 , with lower refractive index and no free-carrier absorption, has been investigated. As electrical issues can mask the optical performance of the BR when evaluated by EQE measurements, a purely optical method that compares the intensity of Raman spectra generated with long wavelength excitation light has been applied. Based on this investigation, MgF 2 /Ag is potentially superior to ZnO:Al/Ag, even when MgF 2 is used in the form of ultrathin layer (few nm, likely island-like). Nevertheless, the novel dual-function n-SiO x /Ag BR outperforms all the other BRs

Клинические вопросы – диагноз метастазах опухолей позвоночника

Catedra Ortopedie şi Traumatologie USMF „N. Testemiţanu”, Republica Moldova Catedra Hematologie, Oncologie USMF „N. Testemiţanu”, Republica Moldova Spitalul Clinic De Ortopedie si Traumatologie, Republica MoldovaSummary: Decision on surgical option of pathological vertebral fractures depends on the character of outbreak metastatic tumor histology, its spread, severity of clinical signs of disease, somatic conditions of the patient and the technical possibilities on making radical spine surgery. Key - words: metastatic spinal tumors, neo-bone formation, tumors of locomotor apparatus Резюме: Решение о хирургической манипуляции патологических переломов позвоночника зависит от характера вспышки гистологии метастатической опухоли, ее распространения, тяжести клинических признаков заболевания, соматического состояния пациента и технических возможностей создания радикальной хирургии позвоночника. Ключевые слова: метастатические опухоли спинного мозга, формирование нео-образований, опухоли двигательного оппорного аппарат

TCO Optimization in Si Heterojunction Solar Cells on p-type Wafers with n-SiOx Emitter☆

Abstract Silicon heterojunction solar cells have largely demonstrated their suitability to reach high efficiencies. We have here focused on p-type c-Si wafers as absorber, considering that they share more than 90% of the solar cell market. To overcome some of the issues encountered in the conventional (n)a-Si:H/(p)c-Si configuration, we have implemented a mixed phase n-type silicon oxide (n-SiOx) emitter in order to gain from the wider bandgap and lower activation energy of this material with respect to (n)a-Si:H. The workfunction of the transparent conductive oxide layer (WTCO) plays also a key role, as it may induce an unfavourable band bending at the interface with the emitter. We have here focused on AZO, a promising alternative to ITO. Different layers with varying WTCO were prepared, by changing relevant deposition parameters, and were tested into solar cells. The experimental results have been explained with the aid of numerical simulations. Finally, for the n-SiOx/(p)c-Si heterojunction with optimized WTCO a potential conversion efficiency well over 23% has been estimated

Self-organized broadband light trapping in thin film amorphous silicon solar cells

Nanostructured glass substrates endowed with high aspect ratio one-dimensional corrugations are prepared by defocused ion beam erosion through a self-organized gold (Au) stencil mask. The shielding action of the stencil mask is amplified by co-deposition of gold atoms during ion bombardment. The resulting glass nanostructures enable broadband anti-reflection functionality and at the same time ensure a high efficiency for diffuse light scattering (Haze). It is demonstrated that the patterned glass substrates exhibit a better photon harvesting than the flat glass substrate in p-i-n type thin film a-Si:H solar cells

Characterizations of nanostructured silicon-carbon films deposited on p-layer by PECVD

Nanostructured silicon carbon films composed of silicon nanocrystallites embedded in the amorphous silicon carbon matrix are prepared by a rf-PECVD system at 250 °C from silane and methane gas mixture highly diluted in hydrogen onto 7059 Corning glass and p-layer deposited on tin oxide substrates by varying rf power from 25 to 65 W. The structural and compositional properties of the films have been investigated. The study demonstrates that rf power controls the crystalline fraction as well as the silicon crystallite size and that p-layer/tin oxide structure enhances the nucleation of silicon grains as compared to Corning glas

Characterizations of nanostructured silicon-carbon films deposited on p-layer by PECVD

Nanostructured silicon carbon films composed of silicon nanocrystallites embedded in the amorphous silicon carbon matrix are prepared by a rf-PECVD system at 250 °C from silane and methane gas mixture highly diluted in hydrogen onto 7059 Corning glass and p-layer deposited on tin oxide substrates by varying rf power from 25 to 65 W. The structural and compositional properties of the films have been investigated. The study demonstrates that rf power controls the crystalline fraction as well as the silicon crystallite size and that p-layer/tin oxide structure enhances the nucleation of silicon grains as compared to Corning glas