abstract |
A clear solution is prepared by reacting metal alkoxide with a mixture of critical amounts of water and/or acid n an alcohol diluted medium. Alkoxides may be Ti(OR) 4 or Ta(OR) 5 , or another metal alkoxide such as Si(OR) 4 in admixture with these alkoxides. Acids may be HCI or HN0 3 . Quarter wave inorganic optical coatings are deposited by applying the alkoxide solution to a substrate then heating the coating at over 350°C. The coatings reduce reflectivity on silicon solar cells. The index of refraction of the coating can be varied by several techniques, including altering the proportion of titanium and silicon in the coating firing temperature, firing atmosphere. Thicknesses of the coating can be controlled by varying the rpm in spin application, withdrawal rate in dipping application, by concentration of the solution, by the type of solvent or the degree of polymerization of the titanium complexes. |