| dc.description.abstract | In this study, first of all, we discuss how different silicon wafer affect the results of surface passivation and solar cell; then we use the quinhydrone(QHY)
as the surface passivation material. The advantages of QHY are rapid, convenient, easy and good passivation effect in chemical immersion. Finally, we apply surface passivation of QHY on silicon solar cells to enhance the open-circuit voltage, fill factor and conversion efficiency.
We measure the effective lifetime value of 30 pieces of silicon wafers, and select respectively the good, normal and bad, three kinds of silicon wafers to process solar cells, whose conversion efficiency are 10.9%, 9.3% and 7.4%, respectively, under the same procedure. Next, we measure effective lifetime of normal silicon wafers on QSSPCD mode with different QHY concentrations and immersion time. We get the best lifetime value, which is 788 µs, and its SRV is 13 cm/s, on the best condition of 0.01 mol/L with immersion time for 60 miuntes. Then, we analyze its surface bonding by the spectrums of C1s, O1s,
and Si2p of XPS, and verify that these QHY-passivation silicon wafers exist the binding signals of Si-O, C-C and C-O on its surface and under the surface for 2 to 4 nm, and this confirms the fact that the process of QHY passivation would improve the surface defects of silicon wafers.
The surface defects of silicon thin film are improved in the way of QHY surface passivation; in addition, its effective lifetime is promoted; then, we process it into a silicon solar cell after we coat the ITO and electrode on it. Finally, measured by AM1.5 light source, the open circuit voltage of QHY-surface-passivation silicon thin film is increased from 553.5 mV to 570.7 mV, its FF is increased from 61.5% to 69.62%, and its conversion efficiency is increased from 11.71% to 12.47%.
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