Cadmium sulfide (CdS) film is combined to p-type silicon substrate in order to fabricate heterojunction solar cells. The optimized efficiency with inserting MoO3 layer between cadmium sulfide and silicon reaches 10.64%, with open voltage, short current density and fill factor of 543 mV, 28.75 mA/cm(2) and 68.13% under traditional condition of 300 degrees C. Finally, the cell's degradation rate is 5.30% in two months, indicating that this is a stable cell design.