process optimization and production experience of concentrator cells

a large project to fabricate silicon concentrator solar cells is described. over 50000 cells of 2.27seconds diameter are fabricated with an overall efficiency of better than 13.8percent measured at 33 suns and 77 degreesc. generation capability of the cells is in excess of 500 kw. the fabrication process described optimized performance ye..

experiments with the cern superconducting 500 mhz cavity

the authors report on a series of experiments with a superconducting 500 mhz single cell cavity of 'spherical' shape fabricated from niobium sheet material. design, fabrication and different room temperature surface treatments of cavity including ion bombardment cleaning are discussed. an experimental test set-up was used, which includes ..

surface analysis of commercially made mirrors

most commercially made mirrors, consisting of a multilayer stack of glass/ag/cu/paint, are made using a wet electroless process, aes, xps and sims have been used for compositional analysis during profiling to reach the ag/glass, ag/cu, and cu/paint interfaces as well as to analyze for impurities present in each layer of the mirror. a five..

automated cylindrical polishing of grazing incidence x-ray mirrors

the use of focusing x-ray systems depends upon the specular reflection at grazing incidence. these systems require mirrors with both excellent surface figure and superior surface finish. in order to obtain an efficient predictable method of fabricating such optics, perkin-elmer's computer-controlled polishing techniques have been adapted ..

automated cylindrical polishing of grazing incidence x-ray mirrors

the use of focusing x-ray systems depends upon the specular reflection of grazing incidence. these systems require mirrors with both excellent surface figure and superior surface finish. in order to obtain an efficient predictable method of fabricating such optics, perkin-elmer's computer-controlled polishing techniques have been adapted ..

introduction to precision machining of metal optics

the development of the single crystal diamond tool and recent improvements in vibration control have made possible the generation of optical quality surface finishes. the marriage of this surface finish quality with the tool path flexibility of numerical control machine tools makes feasible the fabrication of many needed optical component..

press forging of lenses for infrared optical systems

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the dependence of the open-circuit voltage of silicon solar cells on emitter surface parameters

three types of solar cells were fabricated' n/sup +/-p cells and high efficiency n/sup +/-p-p/sup +/ and p/sup +/-n-n/sup +/ back-surface field cells. the only variable parameter with the surface condition on the emitter side' either the surface treatment after metallization of the front (emitter surface) metal coverage factor alpha. the ..

horizontal tunneling and surface band bending' an external technique for wavelength tuning of surface-emitting diodes (leds)

a simple general spectral tuning technique is suggested and shown experimentally to be feasible. the technique, appropriate for shallow junction surface-emitting gaas leds, is repeatable, controllable, reversible, and appears to be completely non-destructive. the tuning capability makes it possible to increase system bandwidth in optical ..

effect of electrolytic oxidation on the q-factor of niobium superconducting resonators

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