高效硅基异质结太阳电池的ITO薄膜研究

INVESTIGATION ON HIGH QUALITY ITO FILMS USED FOR SHJ SOLAR CELL

研究室温下通过直流磁控溅射方法制备高性能非晶ITO薄膜的光电特性,并分析不同结晶度的ITO薄膜对硅基异质结太阳电池性能的影响。结果表明:非晶态的ITO薄膜具有高的载流子迁移率和高的光学透过率;当退火温度高于190℃时,随退火温度的上升,薄膜的结晶性逐渐增强,但其光学性能和电学性能都呈逐渐降低的趋势。通过优化退火温度可获得电阻率为4.83×10^-4Ω·cm、载流子迁移率高达35.3 cm^2(/V·s)且长波段相对透过率大于90%的高性能非晶ITO薄膜。对比普通工艺制备的微晶ITO薄膜,在242.5 cm^2的硅基异质结(SHJ)太阳电池上采用非晶ITO薄膜作透明导电膜,其短路电流密度提高0.32 mA/cm^2,可提升电池的光电转换效率。

Device-quality ITO films used for silicon heterojunction(SHJ)solar cells prepared by DC magnet sputter at room temperature was investigated in the following aspects,the effect of annealing temperature on the optical,electrical and crystalline properties of the ITO films,and the influence of amorphous and micro-crystal ITO film on SHJ solar cell performance with a series of experiments.The results show that the amorphous ITO films have superior transmittance and mobility.However,the optical and electrical properties degrade due to enhancing the film crystallinity when annealed above 190℃.By optimizing the annealing temperature,the ITO’s resistivity of 4.83×10^-4Ω·cm and mobility as high as 35.3 cm^2/(V·s)are obtained,and the transmittance exceeds 90%.Compared with SHJ cells using microcrystalline ITO film,the short-circuit current is gained by 0.32 mA/cm^2 on SHJ cells using amorphous ITO film,and conversion efficiency is increased as well.