Enhanced Efficiency GaAs/InxGa1-xAs QWSC

This paper is devoted to determine the optimum parameters associated with the use of the quantum well for high efficiency solar cells. Two types of material systems are considered, GaAs/InxGa1-xAs and InxGa1-xAs/InyGa1-yAs. Two types of cells are investigated, single quantum well (SQWSC) and multi quantum wells solar cells (MQWSC). For SQW solar cell, the optimized parameters are: well location in the intrinsic region, well width and indium mole fraction x, y. It is found that the optimum location of the quantum well should be away from the high recombination zone around the centre of the space charge region and closer to the p region. The optimum well width and indium mole fraction demonstrated through the paper. For the MQW solar cell, the optimized parameters are barrier to well width ratio (B/W) and spacer thickness. It is found that the barrier to well width ratio should be less than 0.5 to enhance the resonant tunnelling between adjacent wells in order to maximize carrier collection through electron tunnelling. The optimum spacer thickness is about 300 Å to prevent the impurity scattering effect into the space charge region.