Current transport in amorphous silicon n/p junctions and their application as ‘‘tunnel’’ junctions in tandem solar cells

Current transport in a‐Si based n/p (‘‘tunnel’’) junctions is investigated using current‐voltage‐ temperature and quantum efficiency measurements. Currents are nearly ohmic and temperature independent under typical solar cell operating conditions. Incorporating a thin a‐Si(B) p+ layer between the n and p layers and replacing either a‐Si layer with a microcrystalline layer improves the device by reducing the resistance and increasing the recombination. Light soaking improves the devices slightly. These results are consistent with a recently proposed recombination‐tunneling model. Incorporating improved interconnect junctions in tandem solar cell devices improved the initial and stabilized performance.