Recent results on quantum well solar cells

The Quantum Photovoltaic group at Imperial College has pioneered the use of quantum wells in photovoltaic applications, using material supplied by our collaborators in the EPSRC III-V Facility, University of Sheffield, University of Nottingham and the Center for Electronic Materials and Devices. We have shown, in a number of lattice-matched multi-quantum well systems, that quantum wells enhance the output current and efficiency compared to homogeneous cells made from the barrier material and output voltage compared with conventional cells made from the material in the well. This paper discusses recent results in three areas of our work: (1) fundamental studies relevant to the question of whether similar efficiency enhancements will be possible in an ideal cell where radiative recombination dominates, (2) the materials problems we have had to solve in order to enhance the highest efficiency GaAs solar cells with InGaAs wells and (3) the application of quantum well cells in the area of thermophotovoltaics.