We have investigated the impact of carbon co-doping on the performance of boron–doped Czochralski-grown silicon solar cells. It is found that carbon co-doping will deteriorate the initial performance of Aluminium-back-surface-field solar cells before light-induced degradation (LID), owing to the enhancement effect on the formation of oxygen precipitation. However, carbon co-doping can effectively suppress the formation of boron-oxygen complexes in the solar cells, which becomes more significant with an increase of the carbon concentration. Therefore, the performance of carbon co-doped silicon solar cells is better than that of conventional silicon solar cells after LID. All these results are of great significance for the practical application of carbon co-doped silicon solar cells with low LID effect in photovoltaic industry.