Seed-assisted cast quasi-single crystalline silicon for photovoltaic application: Towards high efficiency and low cost silicon solar cells

Abstract

We have demonstrated the seed-assisted cast quasi-single crystalline (QSC) silicon technique to achieve high efficiency solar cells with low cost. Compared to multicrystalline (mc) silicon, the QSC silicon has better material properties, having higher minority carrier lifetime and fewer grain boundaries and dislocations. Furthermore, the 〈100〉 oriented QSC silicon can achieve a lower surface reflectance using alkaline texturing. Based on these two factors, the efficiency of the QSC silicon solar cells with the industrial size has been improved by up to 1% absolutely from the mc-Si counterparts. Compared to the Czochralski (CZ) silicon solar cells, the QSC cells have slightly lower efficiency but high productivity and negligible light-induced degradation. These results suggest a great potential of the QSC silicon applied in photovoltaic industry as the next generation substrate. To make the QSC silicon more competitive in industry, further efforts should be focused on the recycling of seed crystals, the coverage of mono-region and the control of structural defects.