InGaN solar cell requirements for high-efficiency integrated III-nitride/non-III-nitride tandem photovoltaic devices

The use of InGaN photovoltaic devices as a top cell in a tandem solar cell has the potential to improve the power conversion efficiency of multi-junction devices. The effects of the InGaN top cell’s external quantum efficiency, voltage offset, and fill factor on the integrated III-nitride/non-III-nitride solar cell’s power conversion efficiency are presented. The results are summarized into the III-nitride device parameter requirements for top cell applications. The minimum acceptable area ratio between the III-nitride and non-III-nitride subcells in a 3- or 4-terminal device is also determined.