CAJ | 학술논문

为研究热退火对太阳电池用多晶硅的影响,在750～1150℃,N2和O2环境下分别对硅片进行热处理.用傅里叶红外光谱仪和准稳态光电导衰减法测量退火前后的氧碳含量和少子寿命的变化.为了比较,对有相同氧碳含量的直拉硅片进行同样处理.结果发现:在多晶和单晶片中氧碳含量下降很小,意味着没有氧沉淀产生,晶界对碳行为影响不大.多晶硅片在N2和O2环境下,850、950和1150℃下退火,少子寿命都有很大提高,并且在O2中退火比N2中退火少子寿命上升得更多,可能由于在高温退火时大量杂质扩散到晶界处,减少了复合中心.另外,间隙硅原子填充了空位或复合中心从而导致寿命提高.
위연구열퇴화대태양전지용다정규적영향,재750～1150℃,N2화O2배경하분별대규편진행열처리.용부리협홍외광보의화준은태광전도쇠감법측량퇴화전후적양탄함량화소자수명적변화.위료비교,대유상동양탄함량적직랍규편진행동양처리.결과발현:재다정화단정편중양탄함량하강흔소,의미착몰유양침정산생,정계대탄행위영향불대.다정규편재N2화O2배경하,850、950화1150℃하퇴화,소자수명도유흔대제고,병차재O2중퇴화비N2중퇴화소자수명상승득경다,가능유우재고온퇴화시대량잡질확산도정계처,감소료복합중심.령외,간극규원자전충료공위혹복합중심종이도치수명제고.
Oxygen and carbon behaviors and minority-carrier lifetimes in multi-crystalline silicon (mc-Si) used for solar cells are investigated by FTIR and QSSPCD before and after annealing at 750～1150C in N2 and O2 ambient.For comparison, the annealing of CZ silicon with nearly the same oxygen and carbon concentrations is also carried out under the same conditions. The results reveal that the oxygen and carbon concentrations of mc-Si and CZ-Si have a lesser decrease,which means oxygen precipitates are not generated,and grain boundaries in mc-Si do not affect carbon behavior. Bulk lifetime of mc-Si increases in N2 and O2 ambient at 850,950,and 1150C ,and the lifetime of mc-Si wafers annealed in O2 are higher than those annealed in N2, which shows that a lot of impurities in mc-Si at high temperature annealing diffuse to grain boundaries, greatly reducing recombination centers. Interstitial Si atoms filling vacancies or recombination centers increases lifetime.