An intrinsic amorphous silicon oxide and amorphous silicon stack passivation layer for crystalline silicon heterojunction solar cells

- Intrinsic amorphous silicon oxide and amorphous silicon stack passivation layer.
- Photovoltaic parameters were improved by stack passivation layer.
- Crystalline silicon heterojunction solar cells with stack passivation layers.

Intrinsic amorphous silicon oxide (i-a-SiO:H) films were used as passivation layers in crystalline silicon heterojunction (c-Si-HJ) solar cells. The effective lifetime (τeff) and photovoltaic (PV) parameters were improved by controlling the CO2/SiH4 ratio in the i-a-SiO:H rear passivation layer. The enhancement of the open circuit voltage (Voc) and solar cell efficiency (η) caused by the i-a-SiO:H/i-a-Si:H stack passivation layer was investigated. The c-Si-HJ solar cells using an i-a-SiO:H/i-a-Si:H stack passivation layer showed a high Voc and η compared to using a conventional i-a-SiO:H passivation layer. The highest efficiency obtained for a c-Si-HJ solar cell using an i-a-SiO:H/i-a-Si:H stack passivation layer was 19.4% (Voc = 715 mV, Jsc = 34.9 mA/cm2, FF = 0.78).