English title

In this paper, the purpose is to improve the efficiency of triple-junction solar cell by introducing quantum well into GaAs junction. Firstly, InGaP/GaAs/InGaAs triple-junctions solar cell has been simulated. Then, a multiple stepped quantum wells (MSQWs), in which InGaAs well is sandwiched by InGaAsP as stepped layer, and the barrier is GaAs, has been introduced into intrinsic region of single-junction GaAs solar cell. By introducing this MSQWs into middle cell of the triple-junction solar cell, resulting in an increase in short circuit current, the efficiency has been increased to 57.1%. The achieved efficiency is 12% more than the triple-junction cell without using MSQWs. In order to gain the highest possible efficiency, the effect of layers thickness variations and the number of MSQWs have been studied. In this paper, for the purpose of studying the effect of adding MSQWs into cell, Silvaco, Altas, has been applied.