Performance investigation of InxGa1−xAs/GaAs QW and GaAs homojunction solar cell

In this paper, the performance of InxGa1−xAs/GaAs quantum well (QW) solar cell along with graded InxGa1−xAsQW and GaAs homojunction solar cell has been investigated on the basis of incident light wavelength. In addition, two important performance parameters (open circuit voltage (Voc) and short circuit current (Jsc)) have been demonstrated with the variation of indium composition in QW region. The results reveal that, the performance of InxGa1−xAs QW solar cell strongly depends on indium composition and wavelength of incident light. Moreover, it is noticed that GaAs homojunction solar cell is more favorable for shorter wavelength (smaller or equal to 400nm) and shows 41.5% power conversion efficiency but external quantum efficiency (E.Q.E.) is only 10%. Furthermore, InxGa1−xAs graded QW solar cell is best approach for longer wavelength ( greater or equal to 1000nm) and the optimum efficiency has been obtained about 35.47%. However, the Jsc has been improved with the insertion of QW in intrinsic region but Voc and fill factor (FF) slightly reduced compared to homojunction solar cell. Finally, the open circuit voltage and fill factor have been further improved by using average 18% indium content of InxGa1−xAs graded QW solar cell.