Triple-junction amorphous silicon alloy solar cell with 14.6% initial and 13.0% stable conversion efficiencies

We have achieved 14.6% initial and 13.0% stable conversion efficiencies using an amorphous silicon-based alloy in a spectrum-splitting, triple-junction structure. These efficiencies have been confirmed independently by the National Renewable Energy Laboratory. Key factors leading to this major advance include improvements made in the low band-gap amorphous silicon–germanium alloy cell, the $\mathrm{pn}$ tunnel junction between the component cells, and the top conducting oxide.