多晶硅太阳电池预处理及退火工艺研究

RESEARCH ON POLYCRYSTALLINE SILICON SOLAR CELL PRECROCESS AND ANNEALING

在沉积氮化硅薄膜之前采用氨气电离出氢等离子体，先对硅片进行氢等离子体预处理，通过数值分析和实验方法分别研究预处理时间、功率、温度、压力等各参数对钝化效果以及电学性能的影响。在预处理温度450~C，时间200s，射频功率4000W，气体压强200Pa，氨气流量4000sccm／min时，短路电流提高约4％。采用等离子体增强型的化学气相沉积（PECVD）法，在电池表面镀上一层氮化硅膜，实验证实氢等离子体会透过氮化硅进入到硅基体内，从而使少子寿命提高约51xs。低温退火实验表明，430～440％为最优温度，随时间的增加，短路电流有明显提升。

The influence of hydrogen plasma by ammonia ionization preprocessing of MC-Si solar cells before deposition of SiNx thin films was described. The effect of preprocessing time, RF power, temperature and the pressure were investigated. The short circuit current is 4% higher than before. Then the silicon nitride （SiNx ） was deposited for crystalline silicon solar cell by means of plasma enhanced chemical vapor deposition （PECVD） , and the results indicated that the hydrogen plasma could walk through the silicon nitride and the carrier lifetime increased about 5 μs. The low temperature pretreatment could make the short current increased and the best range is 430-440℃.