Study On Post-Treatment Of Amorphous/Crystalline Silicon Heterojunction Solar Cell

Amorphous silicon/silicon heterojunction solar cells（HAC solar cells）have many advantages,such as high transfer efficiency,et al.It is supposed as the next popular production for photovoltaic market.In this paper,various post-treatment techniques are studied.The specific research results are as follows:1、The HAC wafers were heated and irradiated with strong light（Light-thermal treatment）at the same time,and the influence of the parameters such as heating temperature,light intensity,and process time on the modification of cells.It’s found that 180℃is the most optimal temperature,at which,the conversion efficiency of the cell and the minority carrier lifetime of the sample were improved the most.When the temperature remains unchanged,the higher the light intensity,the better the efficiency improvement of the HAC solar cell.In our experiments,no limitation was seen in the light intensity range of 0-20 k W/m².When the cells were treated at a process temperature of 180°C and an irradiation intensity of 12 k W/m² for 60 s,the conversion efficiency increased the most,exceeding 0.7%_abs,and for cells with a basic efficiency of 24.0%,the average efficiency improvement of batch experiments is above 0.5%_abs.2、Compared the modification effects of Light-thermal treatment of HAC solar cells with or without metal grid lines,even with metal grid lines prepared by different methods,the results show that excited carriers recombination in the cell during Light-thermal treatment is one of the reasons that can reduce the surface defects of HAC solar cells.It is found that the thermal process after ITO preparation had obvious impact on the results.The conversion efficiency increasing value of the wafer after Light-thermal treatment is 0.2%_abs higher for the sample without a long-time thermal history than that with a long-time thermal history at a high temperature...3、The defect density in the solar cell could be reduced by heating and soaking with a large current at the same time（Electrical-thermal treatment）to the HAC wafer with the metal grid lines prepared.But high-temperature and high-intensity current would cause irreversible damage to the grids of HAC solar cells,which would reduce the gain in the cell’s efficiency from the improvement of the passivation.Although,under low-temperature conditions,the high current would also cause damage to the grid of the cells.4、Microwave-treatment could improve the passivation of doped-/intrinsic-amorphous silicon stacked films to the surface of the crystallized silicon wafer,and the most obvious improvement happened on the IP stacked films;short-term microwave treatment can improve cell’s conversion efficiency,for the improve the EQE of the HAC solar cells in the short wavelength range.The too long-time microwave treatment would lead to a decrease to the efficiency of the cells.