Solar cell with epitaxially grown quantum dot material

摘要

A solar cell with spaced apart groupings of self-assembled quantum dot layers interposed with barrier layers. Such groupings allow improved control over the growth front quality of the solar cell, the crystalline structure of the solar cell, and on the performance metrics of the solar cell.

主权项

1. A photovoltaic solar cell comprising:
a Ge base with a Ge lattice constant; and a plurality of semiconductor layers formed on the Ge base, the plurality of semiconductor layers including:
first layers of a first semiconductor material, the first semiconductor material comprising InAs, the first layers each having a thickness of about 0.40 nm, the first semiconductor material having a first lattice constant;second layers of a second semiconductor material, the second semiconductor material comprising GaAs, the second layers each having a thickness of about 32.8 nm, the second semiconductor material having a second lattice constant, the second layers being interposed between the first layers; andat least one semiconductor spacer layer comprising InGaAs with an indium concentration of about 1.15%, each of the at least one semiconductor spacer layer having a respective spacer layer lattice constant equal to the Ge lattice constant, the first layers and the second layers being arranged in at least two groupings, each grouping comprising alternating first and second layers that define multiple adjoining pairs of layers, the at least two groupings being separated from each other by one of the at least one semiconductor spacer layer.