热退火对太阳电池用多晶硅特性的影响  

EFFECT OF THERMAL ANNEALING ON CHARACTERISTICS OF MULTICRYSTALLINE SILICON USED FOR SOLAR CELLS

作　　者：任丙彦[1] 勾宪芳[1] 马丽芬[1] 励旭东[2] 许颖[2] 王文静[2] 

机构地区：[1]河北工业大学,天津300130 [2]北京市太阳能研究所,北京100083

出　　处：《太阳能学报》2007年第4期351-354,共4页Acta Energiae Solaris Sinica

摘　　要：对多晶硅片进行三步退火处理,用傅里叶红外光谱仪(FTIR)和准稳态光电导衰减法(QSSPCD)测硅片退火前后氧碳含量及少子寿命,并对单晶硅片做同样处理进行比较。实验发现:经三步退火后,多晶硅比单晶硅氧碳含量下降的幅度大,这表明多晶硅内部形成的氧沉淀多,其体内的高密度缺陷如晶界、位错等对氧沉淀的形成有促进作用。多晶硅与单晶硅少子寿命大大提高,可能是由于高温退火后晶体内部形成氧沉淀及缺陷的络和物可以作为电活性杂质的吸除中心,从而减少了分散的载流子复合中心,提高了硅片的少子寿命。变化趋势的不同与晶体内部结构有关。Oxygen and carbon behavior and minority-cartier lifetimes in multicrystalline silicon （mc-Si） were investigated by means of FTIR and QSSPCD after three step annealing. For comparison, the annealing of czochralski （CZ） silicon was also carried out under the same conditions. The results revealed that oxygen and carbon concentration of mc-Si had a greater decrease than that of CZ-Si, which means the more oxygen precipitates in mc-Si were generated. High density defects of mc-Si such as grain boundaries, dislocations improve formation of oxygen precipitates. Bulk lifetime of mc-Si and CZ-Si greatly increased. The reason of lifetime increase is probably attributed to the fact that lots of oxygen precipitates and defect complex compound generated after three step annealing, which could be suction centers of defect. The reduced cartier decentralized recombination centers resulted in improvement of lifetime of wafer. Tendency diffrence of lifetime was correlated with interior structure of crstalline silicon.

关 键 词：太阳电池 多晶硅 氧沉淀 少子寿命 热退火 

分 类 号：TM615[电气工程—电力系统及自动化]