Hetero-junction with intrinsic thin layer (HIT) solar cells have attracted great attention due to their potential of achieving high conversion efficiency exceeding that of crystalline silicon solar cells. This technology is based on the Sanyo's HIT design that consists of a hetero-junction formed by depositing p-doped hydrogenated amorphous silicon layer a-Si:H(p) on n-doped crystalline silicon c-Si(n) wafer. In addition, these two layers are usually sandwiched by a thin intrinsic amorphous silicon a-Si:H(i), acting as a passivation layer. Sanyo's technology achieved the World Record cell conversion efficiency of 26.7% for a practical cell size of 180 cm(close to the theoretical limit of 29.4%). Even though well-known research and industrial groups in the world also do good works on HIT solar cells achieving over 20% conversion efficiency, none has yet surpassed or approached Sanyo's level. This is partially due to the Sanyo's successful technologies for fabricating "high-quality" doped a-Si:H thin layers. This research project aims to simulate, using AFORS-HET, a new design of HIT solar cells based on p-doped crystalline silicon c-Si(p) wafer, and compare it to Sanyo structure. Also the simulation work will shed light on the recombination's mechanism within the HIT solar cells mainly the surface recombination in the emitter doped amorphous silicon layer.