晶硅太阳电池中Fe-B对与少子寿命、陷阱浓度及内量子效率的相关性

以太阳电池级直拉单晶硅片为材料，利用瞬态微波反射光电导衰减仪研究了硅片分别经过单、双面扩散后Fe-B对与少子寿命τ、陷阱浓度及制备成电池的内量子效率（IQE）的相关性.对于单面扩散后的样品，Fe-B对浓度分布在较大程度上决定了少子寿命分布；对于双面扩散后的样品，Fe-B对浓度显著降低（在135×10¹¹ cm^-3左右），已不及其他杂质和缺陷对少子寿命的影响.结合瞬态微波衰减信号和陷阱模型，对单、双面吸杂前后硅片的陷阱浓度进行数值计算，发现经过扩散 关键词： 少子寿命 陷阱浓度 内量子效率 Fe-B对

Influence of Fe-B pairs on minority carrier lifetime,trapping density and internal quantum efficiency in mono-crystal Si solar cells

Solar-grade p-type Czochralski silicon wafers are doped with phosphorus by single-face and double-face diffusions, and the influence of Fe-B pairs on the minority carrier lifetime, the trapping centers density and the internal quantum efficiency (IQE) of cells (fabricated from the wafers) is analyzed by measuring microwave-detected photo-conductance decay minority carrier lifetime. In the doped wafers with single-face diffusion, the minority carrier lifetime is determined mainly by the density distribution of Fe-B pairs. However, in the doped wafers with double-face diffusion, the minority carrier lifetime is less influenced by the concentration distribution of Fe-B pairs than by other impurities and defects. Numerical calculation based on the combination of the transient voltage signal and the trapping model indicates that the density of trapping centers is reduced by either of diffusion process. On the other hand, detailed analysis of selected specific spots in one wafer with single-face diffusion shows that Fe-B pairs are not the major factor influencing the density of trapping centers. The wafers with different diffusion processes are fabricated into c-Si solar cells and the IQE is measured by using a light beam induced current. The results show that the IQEs of cells with double-face diffusion are higher than those with single-face diffusion, which demonstrates the negative effect of Fe-B pairs on the IQE of solar cells.