We investigated the potential of IO:H thin films and hydrogen doping to improve current density and fill factor for enhancing the performance of silicon heterojunction solar cells. We revealed that a transmittance of 86.7% and work function of 5.4 eV could be achieved by injecting 3 sccm of hydrogen gas. The lattice constant of 1.037 nm at the AB site indicates an anion antibonding tendency, and the work function increases as the Fermi level shifts to the valence band. Based on these findings, we fabricated a silicon heterojunction solar cell and achieved an efficiency of 18.53%, while computer simulation confirmed a conversion efficiency of 24.65%, an open-circuit voltage of 724 mV, and a fill factor of 82.72% at a current density of 41.15 mA/㎠.

Resistance of the front electrode is the highest proportion of the ingredients of the series resistance in crystalline silicon solar cell. While resistance of the front electrode is decreased with larger area, it induces the optical loss, causing the conversion efficiency drop. Therefore the front electrode with high aspect ratio increasing its height and decreasing is necessary for high-efficiency solar cell in considering shadowing loss and resistance of front electrode. In this paper, we used the screen printing method to form high aspect ratio electrode by multiple printing. Screen printing is the straightforward technology to establish the electrodes in silicon solar cell fabrication. The several printed front electrodes with Ag paste on silicon wafer showed the significantly increased height and slightly widen finger. As a result, the resistance of the front electrode was decreased with multiple printing even if it slightly increased the shadowing loss. We showed the improved electrical characteristics for c-Si solar cell with repeatedly printed front electrode by 0.5%. It lays a foundation for high efficiency solar cell with high aspect ratio electrode using screen printing.