| Summary: | 碩士 === 中原大學 === 化學工程研究所 === 97 === In this study, we synthesize a variety of sizes of SiO2 nano-spheres from TEOS, the precursor, with varied ratio of Ammonia Aqua by the Sol-Gel method. The sizes and the distribution of SiO2 nano-spheres on LED-Epitaxy Wafer are observed by Scanning Electron Microscopy (SEM) and Particle Analyzer. Further, we apply SiO2 nano-spheres as a hard mask to obtain patterned and roughing wafer surface by which the light extraction efficiency increases.
For the roughen experiment investigation, we consider several parametric factors with the help of SAS software, and we obtain the optimal value of the model established by the response curve method. Those parametric factors are sphere dimension, 180~500nm, spin-coated rotation speed, 500~3500rpm, and etching depth, 60~300nm, respectively. And their target function is the axial luminous intensity. From the response curve method, all these three factors possess phenomenal degree of influence on the axial luminous intensity. The optimized value of the luminous intensity from calculation is 120.76mcd while these values, 409nm, 500rpm, and 234nm are being designated for the three corresponding factors. The experimental value of the luminous intensity on average is 121mcd with the standard deviation of 2.94mcd while the designated values are being used. Under the optimized roughen condition, the light extraction efficiency increases up to 25% in comparison with non-roughen LED sample.
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