Electrical internal quantum efficiency improved by interval doping method

Electrical internal quantum efficiency is an important parameter for evaluating the utilization degree of the photocurrent density. Amorphous silicon has a quite considerable absorption efficiency of the available incident light. However, the existence of substantial defects in heavily doping amorphous silicon limits the electrical internal quantum efficiency. In this paper, we propose the interval doping method for the amorphous silicon thin-film solar cells. Most of the hot carriers in the amorphous silicon layer will concentrate in the intrinsic region. Due to the lower recombination rate, more hot carriers could be collected by the electrodes. Through the coupled calculation of the optical field and the electric field, it is found that the proposed interval doping amorphous silicon thin-film solar cell’s electrical internal quantum efficiency is significantly enhanced. If the interval doping method is applied to both the top and bottom heavily doping regions, the short-circuit current density will be improved from 9.77 to 12.30  mA/cm2, and the maximum output power will increase from 6.79 to 8.03  W/cm2. All these results indicate that the interval doping method is suitable for improving the performance of the amorphous silicon thin-film solar cells.