基于Quokka优化叉指背接触太阳电池的效率

Optimizing the Efficiency of Interdigitated-Back-Contact Solar Cells Based on Quokka

叉指背接触太阳电池因前表面无栅线所带来的高短路电流及栅线位于背面所获得的组件高密度封装的优势,吸引了众多光伏制造者的关注。然而,由于电池背面的p+发射区和n+背表面场(BSF)区呈交叉分布,在电池制备过程中需进行掩膜技术和激光烧蚀技术的隔离,显然增加了电池制备成本。因此,首先选用Quokka软件从钝化减反层及p+发射区占比的角度探究了优化电池效率的方向,其次利用实验验证了结果的正确性。仿真及实验结果均表明在n+背场区和p+发射区分别沉积SiO2/SiNx/SiOxNy叠层和Al2O3/SiNx/SiOxNy层的钝化效果均优于不含SiOxNy层,而p+发射区与相邻的n+背场区单元宽度越窄且p+发射区占比越高则电池效率越高。

Interdigitated-back-contact solar cells have attracted the attention of many photovoltaic manufacturers because of the advantages for high short-circuit current caused by the zero-finger on the front and high density packaging of the modules with fingers located on the rear.However,due to the interdigitated distribution of p+emitter and n+back surface field(BSF)region on the rear of the cell,the isolation of mask technology and laser ablation technology is needed in the cell fabrication process,which obviously increases the cost.Therefore firstly,the direction of optimizing cell efficiency from the perspective of passivation antireflection layer and p+emitter ratio was explored by the Quokka software.Secondly,the experiments were carried out to verify the correctness of the results.The simulation and experimental results show that the passivation effects of SiO2/SiNx/SiOxNystacks and Al2O3/SiNx/SiOxNylayers deposited on n+BSF region and p+emitter respectively are better than that of without SiOxNylayer.The narrower the unit width between p+emitter and n+BSF region,and the higher the p+emitter ratio,the higher the cell efficiency.