Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 2010 · 15 citations · 5 references
EngineeringElectrical EngineeringMaterials ScienceOptoelectronicsSemiconductor DevicesSemiconductor MaterialsOptical Properties Of SemiconductorsPhotovoltaic DevicesQuantum WellsSemiconductor PhysicsSolar CellsStrain EngineeringBiaxial StrainCompressive StrainMulti-junction Solar CellsNanostructured Solar CellsOptical Loss MechanismsOptical Path LengthQuantum Well Solar CellsRadiative Recombination
It is possible to tailor the band gap of the strain-balanced quantum well solar cell to match the local solar spectral conditions by altering the quantum well depth. This has led to a recent single-junction world-record efficiency of 28.3%, as well as giving advantages for current matching in multi-junction solar cells. Radiative recombination is the dominant loss mechanism for the strain-balanced quantum well solar cell, so practical improvements focus on techniques for light management in the cell, such as enhancing the optical path length with epitaxial mirrors. Furthermore, the compressive strain in the quantum wells suppresses emission into TM-propagating modes, reducing the overall optical loss and increasing the cell efficiency. As biaxial strain can only be engineered into a cell on the nanoscale, quantum well solar cells are seen to have a fundamental efficiency advantage over bulk semiconductor cells.
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Strain-balanced GaAsP/InGaAs quantum well solar cells
Nicholas J. Ekins‐Daukes, K.W.J. Barnham, J.P. Connolly et al. · Applied Physics Letters · 1999 · 274 citations