Tandem solar cells are provided that are more cost-efficient manner and can reach much higher power conversion efficiency compared to previous technologies. In some aspects, a tandem solar cell includes a first subcell configured to absorb a first portion of a solar spectrum, wherein at least one layer of the first subcell is polycrystalline, and a second subcell configured to absorb a second portion of the solar spectrum, wherein the second subcell is electrically connected to the first subcell through a conductive contact, and includes at least one textured surface.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
 This invention was made with government support under DOE Cooperative Agreement No. DE-EE0004946 awarded by the U.S. Department of Energy. The government has certain rights in the invention.