Patent ID: 10636927

Abstract:
A solar cell stack having a first semiconductor solar cell that has a p-n junction of a first material with a first lattice constant and a second semiconductor solar cell that has a p-n junction of a second material with a second lattice constant. The solar cell stack has a metamorphic buffer that includes a sequence of a first, lower layer and a second, center layer, and a third, upper layer, and includes an InGaAs or an AlInGaAs or an InGaP or an AlInGaP compound. The metamorphic buffer is formed between the first and second semiconductor solar cells and the lattice constant in the metamorphic buffer changes along the buffer's thickness dimension. The lattice constant of the third layer is greater than the lattice constant of the second layer, and the lattice constant of the second layer is greater than the lattice constant of the first layer.