Electronic spray deposition

Particularly desirable among film deposition processes are solution-based techniques, because of the relative simplicity and potential economy of these approaches. However, the covalent character of the metal chalcogenides, which provides the benefit of the desired electronic properties (e.g., high electrical mobility), represents an important barrier for solution processing. Several methods have been developed to overcome the solubility problem, including spray deposition, bath-based techniques, and electrochemical routes, each of which will be discussed in later chapters. In this chapter, a very simple dimensional reduction approach will be considered as a means of achieving a convenient solution-based route to film deposition. 

Figure 3.29. Scanning electron microscope picture of the electrode-electrolyte structure along a perpendicular cut. Top screen-printed Lao.jSro 4CO0 FeogOj positive electrode. Middle spray-deposited electrolyte, YSZ = 8 mol% YjOg stabilised ZrOj. Bottom negative electrode, NiO and YSZ in ratio 7 3, in cermet CeOj. (From D. Perednis and L. Gauckler (2004). Solid oxide fuel cells with electrolytes prepared via spray pyrolysis. Solid State Ionics 166,229-239. Reprinted by permission from Elsevier.)...

Fignre 5.2f and g shows the metalhzation process on the 3-D microstmctnres. By spray coating, the photoresist fihn is formed on the 3-D topographic stmctnres and patterned by photolithography, (f) Ti/An for cnrrent coUectors is formed by electron-beam deposition and snbseqnent lift-off process, (g) Catalyst layers of the anode and cathode are formed by electroplating Pt-Rn for the anode and Pt for the... 

Figure 5. (a) OER overpotentials in sputtered Fe203 (b) scaiming electron microscopy (SEM) of sputtered Fe203 (c) SEM of photoactive spray-deposited Fe203... 

Decreasing operation temperature of solid oxide fuel cells (SOFCs) and electrocatalytic reactors down to 800-1100 K requires developments of novel materials for electrodes and catalytic layers, applied onto the surface of solid electrolyte or mixed conducting membranes, with a high performance at reduced temperatures. Highly-dispersed active oxide powders can be prepared and deposited using various techniques, such as spray pyrolysis, sol-gel method, co-precipitation, electron beam deposition etc. However, most of these methods are relatively expensive or based on the use of complex equipment. This makes it necessary to search for alternative synthesis and porous-layer processing routes, enabling to decrease the costs of electrochemical cells. Recently, one synthesis technique based on the use... 

Fig. 2.2 Structures and scanning electron microscopy (SEM) photographs of different MALDI matrices deposited onto a stainless steel plate. Lower SEM photographs show E. coli cells cocrystallized with different MALDI matriees (matrix applied with a spray deposition technique). Arrows point to intact cells within the erystalline matrix. (Adapted from Toh-Boyo et al. 2012, eopyright American Chemical Society)...

Dried spray deposits on leaf surfaces have been studied using scanning electron microscopy (SEM), while secondary electron emission, cathodoluminescence, and X-ray microanalysis have been used to examine the phytotoxic effects of pesticides or surfactants on the leaf epidermis. Using these techniques, it has been demonstrated that uptake continued after spray deposits have visibly dried. ... 

Another growing apphcation that overlaps the electrically functional area is the use of transparent conductive coatings or tin oxide, indium—tin oxide, and similar materials in photovoltaic solar ceUs and various optic electronic apphcations (see Photovoltaic cells). These coatings are deposited by PVD techniques as weU as by spray pyrolysis, which is a CVD process. 

Hollingsworth, J. A. Buhro, W. E. Hepp, A. F. Jenkins, P. P. Stan, M. A. 1998. Spray chemical vapor deposition of CuInS2 thin films for application in solar cell devices. Chemical Aspects of Electronic Ceramics Processing, edited by Kumta, P. N. et al., MRS Symp. Proc., Vol. 495, Materials Research Society, Pittsburgh, PA, pp. 171-176. 

In the first of these methods, the HPLC effluent is sprayed or otherwise deposited on a moving belt, most of the solvent is removed by heating and pumping, then the sample is carried directly into the ionization compartment352. Ionization may be of the electron impact or chemical type (see Section III.B.6.b). 

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