Optimization of the Electrode Formation Mechanism for Crystalline Silicon Heterojunction Solar Cells

Abstract

The screen-printing process for making good contact of electrodes with the top layer of solar cells is crucial for enhancing the electrical properties of a solar cell. This paper reports the experimental approach adopted for the process of electrode formation and the resulting shape of electrodes in silicon-based heterojunction (SHJ) solar cells. It was observed that good contact between electrodes and the top transparent conductive oxide (TCO) layer strongly depends on the squeegee pressure, curing temperature, and curing time. By optimizing the squeegee pressure at 0.350 MPa, snap-off distance of 1.4 mm, squeegee speed of 80 mm sec−1, curing temperature of 180 °C, and curing time of 30 min, respectively for which the height to width ratio (aspect ratio) of the fabricated electrodes was achieved around 0.66. The results have been verified through 3D laser profiler, field emission scanning electron microscopy (FE-SEM), transfer length method (TLM), and Light current-voltage (LIV) measurements. The SHJ solar cells were fabricated using an optimized condition and successfully achieved splendid properties of short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF), and efficiency (η) up to 40.57 mA cm−2, 723 mV, 81.03%, and 23.79%, respectively.