| Title |
A Study on MgF_2/CeO_2 AR Coating of Mono-Crystalline Silicon Solar Cell |
| Keywords |
Cz Si wafer ; AR coating ; MgF_2 ; CeO_2 ; Fire-through ; Texturing ; Refractive index ; Reflectance |
| Abstract |
This paper presents a process optimization of antireflection (AR) coating on crystalline Si solar cells. Theoretical and experimental investigations were performed on a double-layer AR (DLAR) coating of MgF_2/CeO_2. We investigated CeO_2 films as an AR layer because they have a proper refractive index of 2.46 and demonstrate the same lattice constant as Si substrate. RF sputter grown CeO_2 film showed strong dependence on a deposition temperature. The CeO_2 deposited at 400°C exhibited a strong (111) preferred orientation and the lowest surface roughness of 6.87 AA. Refractive index of MgF_2 film was measured as 1.386 for the most of growth temperature. An optimized DLAR coating showed a reflectance as low as 2.04% in the wavelengths ranged from 0.4μ{ textrm} m to 1.1μ{ textrm} m. We achieved the efficiencies of solar cells greater than 15% with 3.12% improvement with DLAR coatings. Further details on MgF_2, CeO_2 films, and cell fabrication parameters are presented in this paper. |