In this paper, a new process for the formation of hemispherical structures as an omni-directional anti-reflection (omni-AR) coating in solar cell is reported. We also demonstrated the simulation results of the angular and spectral dependences of the total reflectivity on various micro-structured surfaces. Close to zero reflection can be achieved in some micro-structured surfaces over an extended spectral region for large ranges of incident light angles. Daily generated current in such hemispherical solar cells hence enhanced to 1.5 times of bulk silicon solar cells. The impact of feature size, density, shape and refractive index has all been investigated. The experimental results agree reasonably well with the theoretical work. Such an omni-AR structure offers an attractive solution to current bulk crystalline silicon solar cells, as well as thin film, organic and future quantum based solar cells.