为了得到优化的扩散工艺，通过改变扩散时间来改变Ⅱ类单晶硅片电池发射区的掺杂浓度和结深，研究了扩散时间对太阳电池性能的影响。通过太阳电池单片测试仪(XJCM-9)测试电池性能。得到了实验条件下优化的扩散工艺，此工艺既考虑了短路电流，又兼顾到开路电压。最优扩散工艺参数为：扩散温度850℃，主扩时间和再分布时间分别为40min和15min。此时电池的开路电压、短路电流密度、填充因子和转换效率分别为657mV、33.57mA/cm2、74.36%和16.4%。优化扩散工艺制备的电池效率较原扩散工艺电池提高了约0.3%。

To obtain the optimum diffusion process, the doping concentration and junction depth of solar cells based on type-II silicon wafers was changed by using diffusion time. The influence of diffusion time on the performance of solar cells was investigated. The performance of solar cells was measured by solar cell tester (XJCM-9). The optimum diffusion process under the experimental condition was obtained. This diffusion process takes both short circuit current and open circuit voltage into account. The optimum parameters of the diffusion process are listed as follows: the diffusion temperature is 850℃, the main diffusion time and redistribution time are 40min and 15min, respectively. The open circuit voltage, short circuit current density and fill factor of the solar cells prepared under these parameters are 657mV, 33.57mA/cm2 and 74.36%, respectively. The obtained maximum conversion efficiency is 16.4%, which is 0.3% higher than that of the solar cells fabricated by normal diffusion process.