高绒度掺硼氧化锌透明导电薄膜用作非晶硅太阳电池前电极的研究

Study of boron-doped zinc oxide film serving as front contact with high haze used in amorphous silicon thin film solar cells

将自行研制的具有优异陷光能力的掺硼氧化锌用作p-i-n型非晶硅太阳电池的前电极,并且将传统商业用U型掺氟二氧化锡作为对比电极.相比表面较为平滑的掺氟二氧化锡,掺硼氧化锌表面大类金字塔的绒面结构会在本征层生长过程中触发阴影效应,形成大量的高缺陷材料区和漏电沟道,进而恶化电池的开路电压和填充因子.在不修饰掺硼氧化锌表面形貌的情况下,通过调节非晶硅本征层的沉积温度来消弱高绒度表面形貌引起的这种不利影响,对应的电池开路电压和填充因子均出现提升.在仅有铝背电极的情况下,在本征层厚度为200 nm的情况下,以掺硼氧化锌为前电极的非晶硅太阳电池转换效率达7.34%(开路电压为0.9 V,填充因子为70.1%,短路电流密度11.7 mA/cm2).

Boron-doped zinc oxide （BZO） deposited by metal organic chemical vapor deposition （MOCVD） method is used as front contact in amorphous silicon thin film solar cells. Asahi-U type SnO2 ： F is used as the reference front contact for comparison. When the a-Si： H intrinsic layer thickness is changing changed, the performance of a-Si： H solar cells shows different evolution trends. These different results can be understood from the shadowing effect during the growth of intrinsic silicon material, which is caused by the as-grown pyramid texture in the surface of BZO substrate. In order to reduce this negative effect on the performance of solar cells, the deposition temperature of the a-Si： H intrinsic layer is optimized, to thereby improving improve the open circuit voltage and fill factor. The conversion efficiency of a-Si ：H solar cells can reach up to 7.34%, with the thickness of absorber layer being only around 200 nm. and only Al back reflector is being used.