IBC太阳电池非均匀掺杂衬底结构参数的优化研究

Structure parameter optimization of the non-uniform doped substrate of IBC solar cells

利用TCAD半导体器件仿真软件设计了一种具有非均匀掺杂衬底结构的N型插指背结背接触(IBC)单晶硅太阳电池。全面系统地分析了非均匀掺杂衬底结构的表面浓度和扩散深度对IBC太阳电池外量子效率、短路电流密度、开路电压、填充因子及转换效率的影响。仿真结果表明:非均匀掺杂衬底结构在一定程度上可提高IBC太阳电池的转换效率;非均匀掺杂衬底结构当扩散深度一定时,存在最优的表面浓度,使得IBC太阳电池的转换效率最高,且非均匀掺杂衬底结构的扩散深度越浅,最优的表面浓度越高。当扩散深度为1.9μm时,最优的表面浓度为3×1016cm-3,电池效率为22.86%;当扩散深度减小到1.1μm时,最优的表面浓度大于1×1018cm-3,电池效率大于23.092%。当非均匀掺杂衬底结构的表面浓度一定时,随着扩散深度的增大,IBC太阳电池转换效率随之降低。

A N-type interdigitated back contact （IBC） crystalline silicon solar cell with the non-uniform doped substrate structure was designed by using the TCAD concentration and the diffuse depth of the semiconductor device simulation software. The influences of the surface non-uniform doped substrate structure on the IBC solar cell＇ s external quantum efficiency, short-circuit current density, open-circuit voltage , fill factor and conversion efficiency were studied comprehensively and systematically. The simulation results show that the non-uniform doped substrate structure can improve the IBC solar cell conversion efficiency to a certain extent; when the diffuse depth of the non-uniform doped substrate structure remains a fixed value, there is an optimal surface concentration, which makes the IBC solar cell reach the maximum conversion efficiency. With the diffuse depth decreasing, the optimal surface concentration increases. When the diffusion depth was 1.9μm, the optimal surface concentration was 3 × 10^16cm-3, and the solar cell conversion efficiency was 22.86% ; When diffusion depth decreased to 1.1 μm, the optimal surface concentration was greater than 1 × 10^18 cm-3, and the solar cell conversion efficiency was more than 23. 092%. When the non-uniform doped substrate＇ s surface concentration remains a fixed value, the IBC solar cell conversion efficiency decreases with the increase of the diffusion depth.