Role of back-side indium tin oxide on the degradation mechanism of silicon heterojunction solar cells

Silicon heterojunction (SHJ) solar cells with only front-side indium tin oxide (ITO) and those with both sides ITO were subjected to accelerated degradation in argon ambient, at temperature of 90°C and illumination intensity of 100mW/cm
²
. Between 0 and 500 hours of exposure, the cells were removed iteratively for current density-voltage (JV), quantum efficiency (QE) and Suns- Voc measurements. While cells with both sides ITO demonstrated stability in performance after 500 hours of exposure, the cells without the rear-side ITO degraded in performance, with an average open-circuit voltage (Voc) loss of about 12% and an average efficiency (n) loss of about 16%.