Reverse leakage current mechanism in crystalline silicon solar cells with N+/P junctions

We have investigated the reverse leakage current mechanism of screen-printed Ag contacts on P-diffused crystalline Si solar cells of different efficiencies. The current-voltage measurements have been carried out in the temperature range of 175-450 K in steps of 25 K. The leakage current is independent of temperature for T<; 300 K indicating the tunneling mechanism to be dominant at these temperatures in the cells of both efficiencies. The cell with higher efficiency exhibited higher leakage current compared to the lower efficiency cell as also evidenced by the lower activation energy obtained from the Arrhenius plot of reverse current. The higher leakage current in higher efficiency cell could be due to increased Schottky junction formation area compared to the lower efficiency cell.