Mechanically stacked 4-terminal III-V/Si tandem solar cells

Transparent Conductive Adhesives for Tandem Solar Cells Using Polymer–Particle Composites

“…For 2T devices, the interlayer needs to (1) be transparent in the wavelength range that the bottom cell absorbs, (2) possess sufficient conductivity in the out-of-plane direction to transfer current between the cells with minimal series resistance losses, and (3) have adhesive strength and durability to hold the cells together over the lifetime of the module. Interlayers formed by wafer bonding satisfy these three criteria and have been used to fabricate >30% efficient 2T III–V/Si tandem cells. , However, wafer bonding requires extremely clean, polished surfaces, resulting in a process that is costly, with low yields, and is incompatible with textured silicon . For inexpensive, 2T tandem cells, TCA materials must be developed that are compliant and compatible with the micron-scale-textured silicon.…”

“…Interlayers formed by wafer bonding satisfy these three criteria and have been used to fabricate >30% efficient 2T III−V/Si tandem cells. 10,11 However, wafer bonding requires extremely clean, polished surfaces, resulting in a process that is costly, with low yields, and is incompatible with textured silicon. 12 For inexpensive, 2T tandem cells, TCA materials must be developed that are compliant and compatible with the micron-scale-textured silicon.…”