氧化铝/氮化硅双层膜晶硅钝化的开尔文探针力显微镜研究

Kelvin probe force microscopy study on the passivation of aluminum oxide/silicon nitride bilayer for crystalline silicon

对晶体硅(c-Si)太阳能电池而言,氧化铝(AlO_(x))是一种广泛使用的钝化材料,因为它具有优异的沉积保形性和良好的钝化质量.为了确保AlO_(x)发挥其良好的钝化效果,在沉积后退火并氢化处理是必不可少的.通过在AlO_(x)薄膜上沉积氢化氮化硅(SiNx:H)来实现氢化,利用开尔文探针力显微镜研究了在不同热处理和氢化作用下,AlO_(x)/SiN_(x):H双层薄膜功函数的变化,并基于沉积薄膜所含氢与固定电荷展开了讨论.发现钝化质量和功函数之间有相关性,影响因素包括薄膜厚度、氢化与热处理顺序.

Aluminium oxide(AlO_(x))is a widely used passivation material as far as the crystalline silicon(c-Si)solar cells are concerned because of its perfect deposition conformality and good passivation quality.To ensure a good passivation quality,a post-deposition treatment of AlO_(x)layers including hydrogenation is considered indispensable.In this study,hydrogenation is realized by depositing a hydrogenated silicon nitride(SiNx:H)on AlO_(x)layer.The variant function of AlO_(x)/SiN_(x):H bilayers under different thermal treatments and hydrogenation is investigated.Discussion based on layer contented hydrogen and fixed charge is conducted.A strong correlation between passivation quality and work function is identified,where the correlation is found to be influenced by layer thickness,thermal treatment sequence and hydrogenation.