Deep-level transient spectroscopy of solar cells based on HJT architecture under influence of electron irradiation
In this work, we study the effect of irradiation as in low Earth orbits on heterojunction technology structures (p)a-Si:H/(n)c-Si. To compare the photoelectric properties, three samples were created: the original (without electron irradiation) and two irradiated ones with the fluence of irradiation of 5·1014 cm–2 and 1·1015 cm–2. Catastrophic deterioration of photoelectrical properties were observed for this irradiation: short-circuit current falls almost by two times, and open-circuit voltage drops by 150–200 mV. By measurements of deep-level transient spectroscopy, formation of A-center (V-O, vacancy-oxygen) with 0.16–0.17 eV in silicon wafer in bulk material were shown, and its concentration increases with growth of irradiation dose. Its arising leads to degradation of solar cells.