Innovating Process in Heterojunction Back Contact Silicon Solar Cells Using Shadow Metal Masks

We present a very simple process to fabricate silicon heterojunction back contact (HBC) solar cell. This process can easily form a backside structure using in situ masks without particular patterning process. Based on our silicon heterojunction (SHJ) solar cell process conditions, we optimize the process for HBC solar cell. The intrinsic a-Si: H layer and p-type a-Si: H layer process conditions were adjusted to improve to FF and efficiency. Applying these adjust, we obtained 18.1% efficiency of the HBC solar cell with V_OC of 684 mV, J_SC of 38.3 mA/cm², FF of 69.1%. The key factors affecting FF and performance of the HBC solar cell are also discussed.