Patent ID: 7868247

Claim:
A method of forming a photovoltaic device comprising a multiple quantum well portion comprising a plurality of quantum wells and a plurality of barriers, the quantum wells and barriers being disposed on an underlying layer, the barriers alternating with the quantum wells, one of the plurality of quantum wells and the plurality of barriers comprised of tensile strained layers and the other of the plurality of quantum wells and the plurality of barriers comprised of compressively strained layers, the tensile and compressively strained layers having elastic properties, comprising: selecting compositions and thicknesses of the barriers and quantum wells using an equation taking into account the elastic properties of the tensile strained layers and the compressively strained layers such that each period of one tensile strained layer and one compressively strained layer exerts substantially no shear force on a neighboring structure; providing the underlying layer; and forming the quantum wells and barriers on the underlying layer according to the derived compositions and thicknesses.