ABSTRACT The main purpose of this master’s project is to review of literature about the study optical enhancement of hetero-junction silicon-based solar cell. The impurities added have a dominant role of efficiencies such as boron and phosphorus. These are usually expressed in terms of p-type and n-type respectively. Then combining the p-type and n-type semiconductor, the heterojunction of dissimilar semiconductor materials was made. The usual method described in the literature was based on the plasma-enhanced chemical vapor deposition and radio-frequency magnetron sputtering for the fabrication of the silicon hetero-junction solar cells. In order to characterize the parameters mention earlier, the illuminated J-V characteristics and spectrophotometers are used. Generally, the conversion efficiency silicon solar cell is depending on the window layer, an antireflection layer, thickness of material and intensity of photon. The fluctuation of short-circuit current and open-circuit voltage are different with different antireflection layer, the thickness of materials and intensity of light (dark or illumination). The silicon layer enhanced efficiency by 15.27% whereas the ITO layer by 19.58% experimentally. When we compared the conversion efficiency of SiO and ITO antireflection, it is much different. The conversion efficiency of ITO is greater than SiO 2 The ITO layer was superior to SiO 2 2. layer in terms of optical and electrical performance. The best thickness for the c-Si layer is obtained with value of 5×10 4 nm which is thick enough for absorbing light. Keywords: hetero-junction, p-type, n-type, plasma-enhanced chemical vapor deposition, radio frequency magnetron sputtering