| Summary: | 碩士 === 南臺科技大學 === 機械工程系 === 105 === This study investigated the process of which multi-crystalline silicon (mc-Si) surfaces texturization by acid etching. It includes diamond wire cutting of mc-Si silicon ingots followed by grinding, sand blasting and acid etching on the surfaces of the cutout mc-Si specimens. The purpose is trying to create solar cells with low reflectance. Hence higher solar cell efficiency may be obtained. To acid etching, different etching solutions were prepared with HF/HNO3/H2O in different ratios and used to etch the mc-Si surfaces for durations corresponding to different time parameters,so that the recessed structures were formed on the surfaces. Then, the effects of different parameters and steps on the roughness, topography and reflectance of the textured mc-Si surfaces were examined using Scanning Electron Microscopy (SEM), Laserscanning Confocal Microscopy(LSCM) and Ultraviolet-Visible Spectrophotometry(UV-Vis). The results of this study revealed the following. (i) Adding the grinding and sand blasting procedures before acid etching are able to effectively remove cutting marks and reduce roughness; sand blasting after flattening enabled the formation of small potholes that provided the starting points for subsequent etching; and the structures obtained from preforming etching were able to accelerate reactions and reduce the use of etching solutions in subsequent chemical etching. (ii) Etching solutions prepared in different ratios and etching times were able to change textured topography in the way that higher HF content increased the etching rates and thus made the etching effects on the mc-Si specimens more prominent and also in the way that longer etching time enabled etching solutions to fully react with all parts of the surfaces so that the surfaces of the mc-Sispecimens were evenly textured and the recessed structures became more prominent. (iii) The textured mc-Si surfaces were able to reduce the reflectance bysunlight from 38% to below 16%.
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