Solar energy is acknowledged as one of the renewable energy that can be used for the next generation, but the low energy conversion of solar is the main concern of current technology. Previous research has shown that there are several methods to increase efficiency, one of them is to change the performing structural of the solar cell. In this work, the efficiency of the conventional solar cell will be further increased by changing the cell thickness and emitter doping concentration. By using this method the amount of reflection can be reduced and at the same time increasing the absorption of the solar cell. Interdigitated-Back Contact (IBC) solar cell will be used for this work. This structure is chosen because of the absence of front contact that can block a few of light to go through into solar cell. The goal is to find the optimum parameter that can generate high efficiency. Sentaurus TCAD simulation is used to create the solar cell structure and to do a detailed analysis of performance parameters. Sentaurus TCAD tool is used to generate P-V curve and I-V curve which then be used to evaluate the efficiency of Interdigitated-Back Contact (IBC) solar cell.