Thin deposition technologies

StiU another method used to produce PV cells is provided by thin-fiLm technologies. Thin films ate made by depositing semiconductor materials on a sohd substrate such as glass or metal sheet. Among the wide variety of thin-fiLm materials under development ate amorphous siUcon, polycrystaUine sUicon, copper indium diselenide, and cadmium teUuride. Additionally, development of multijunction thin-film PV cells is being explored. These cells use multiple layers of thin-film sUicon alloys or other semiconductors tailored to respond to specific portions of the light spectmm. 

Other uses are in thin film technology where coatings are applied by vacuum deposition. Tungsten boats, or coils fabricated from wire are heated by direct resistance heating and used to evaporate Ag, Al, Au, B, Ba, Ce, Cr, Fe, In, Mg, Mn, Ni, Pa, Pt, SiO, Te, V, Zn and Zr. 

The photovoltaic industry is slowly expanding with continuous advances in materials and thin-film technology. The deposition techniques, which were at first based mostly on sputtering and evaporation, are now increasingly relying on CVD. 

Compares ink jet printing and vapor phase deposition technologies for thin films preparation... 

Deposition technology, thin film, 23 6-7 Deposits, cooling system, 26 138 Depreciation, 9 539 book-basis, 9 540... 

The micromagnetic structure is directly related to the microstructure and chemical inhomogenities in the layer. The materials used and the deposition technology as well as the parameters play an important role. Thin-film growth, nudeation processes in relation to the deposition parameters, are very important for understanding the thin film microstructure. The relationships between sfd and recording properties are not necessarily valid for media with perpendicular anisotropy as the demagnetizing field can be more important than sfd. 

Bunshah, R. F. In Deposition Technologies for Thin Film Coatings Bunshah, R. F., Ed. Noyes Park Ridge, NJ, 1982 p 4-5. 

In order to maintain the advantage of the microfabrication approach which is intended for a reproducible production of multiple devices, parallel development of membrane deposition technology is of importance. Using modified on-wafer membrane deposition techniques and commercially available compounds an improvement of the membrane thickness control as well as the membrane adhesion can be achieved. This has been presented here for three electrochemical sensors - an enzymatic glucose electrode, an amperometric free chlorine sensor and a potentiometric Ca + sensitive device based on a membrane modified ISFET. Unfortunately, the on-wafer membrane deposition technique could not yet be applied in the preparation of the glucose sensors for in vivo applications, since this particular application requires relatively thick enzymatic membranes, whilst the lift-off technique is usable only for the patterning of relatively thin membranes. 

To reduce expense, efforts are made to exploit integrated thin film technologies. For example, arrays have been produced via thin film deposition of the pyroelectric onto a sacrificial layer, e.g. a suitable metal or polysilicon, which is then selectively etched away. Thermal isolation of the pyroelectric element is achieved through engineering a gap between it and the ROIC silicon wafer. Yias in the supporting layer permit electrical connections to be made between the detector and the wafer via solder bonds. Imaging arrays have been produced in this way incorporating sputtered PST and sol-gel formed PZT films. 

Refs. [i] Hassel AW, Diesingb D (2002) Thin Solid Films 414 296 [ii] Strehblow HH (2003) Passivity of metals. In AlkireRC and Kolb DM (eds) Advances in electrochemical science and engineering, vol. 8. Wiley-VCH, Weinheim, pp 271-374 [iii] Kern W, Schuegraf KK (2002) Deposition technologies and applications introduction and overview. In Seshan K (ed) Handbook of thin film deposition techniques principles, methods, equipment and applications. William Andrew, Noyes, p 19... 

In spite of its promise, the thin-film technology has been unable to reduce the cost of solar modules, owing to low deposition rates that have led to low capital utilization of expensive machines. The yields and throughputs have been low. These plants need better inline controls. In recent times, owing to manufacturing problems, some corporations have shut down their thin-film manufacturing facilities. Clearly, easier and faster deposition techniques leading to reproducible results are needed. Also, deposition techniques that would not result in a substantial drop in efficiency from laboratory scale to module scale are required. 

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