全TOPCon电池正面多晶硅层硼掺杂工艺

Boron Doping Technology for the Front Polysilicon Layer of Full TOPCon Cells

为提升隧穿氧化层钝化接触(TOPCon)电池光电转换效率,本文通过高温扩散在n型TOPCon电池正面制作p型隧穿氧化层钝化接触结构,提升发射极钝化性能,减少正面金属复合。本文研究了不同沉积时间、推进温度、推进时间等工艺参数对实验样品钝化性能及掺杂曲线的影响。实验结果表明,当沉积时间为1500 s,推进温度为920℃,推进时间为20 min时,掺硼多晶硅层可获得较优的钝化性能及掺杂浓度,其中样品多晶硅层硼掺杂浓度达到1.40×10^(20)cm^(-3),隐开路电压(iV_(oc))大于720.0 mV。依据该参数制备的TOPCon电池光电转换效率可达23.89%,对应的短路电流密度为39.36 mA/cm^(2),开路电压(V_(oc))达到726.4 mV,填充因子(FF)为83.54%。

In order to improve the efficiency of tunneling oxide passivated contact(TOPCon)cells,a p-type tunneling oxide passivation contact structure was fabricated on the front of N-type TOPCon cells through high-temperature diffusion,improving the emitter passivation performance and reducing front metal recombination.The effects of different deposition time,drive-in temperature,drive-in time and other process parameters on the passivation performance and doping curve of experimental samples were investigated.The experimental results show that when the deposition time is 1500 s,the drive-in temperature is 920℃,and the drive-in time is 20 min,the boron doped polysilicon layer can achieve better passivation performance and boron doping concentration,with the doping concentration of sample polycrystalline silicon layer reaching 1.40×10^(20)cm^(-3).The implied open circuit voltage(i V_(oc))is greater than 720.0 mV.The photoelectric conversion efficiency of TOPCon cells prepared based on this parameter can reach 23.89%,corresponding to a short-circuit current density of 39.36 mA/cm^(2),the open circuit voltage(V_(oc))is 726.4 mV,and the fill factor(FF)is 83.54%.