26.7% AM0, 30.2% AM1.5G dual junction solar cell with 50x InGaAs quantum wells, GaAsP strain compensation, and distributed Bragg reflector

Dual junction upright solar cells composed of a homojunction InGaP top cell and a heterojunction InGaP/GaAs bottom cell incorporating 50 layers of In0.1Ga0.9As with GaAs0.9P0.1 and a 12-pair A10.9Ga0.1As/A10.1Ga0.9As distributed Bragg reflector were designed for operation under either AM0 or AM1.5G and grown by MOVPE. The QWs allowed an increase in current density of 1.98 mA/cm2 under AM0 (1.07 mA/cm2, AM1.5G design), with an exhibited Voc reduction of only 10 mV as compared to a control tandem without QWs or a DBR. This lead to a efficiency increase of 2.55% absolute under AMO (1.79% absolute, AM1.5G design). Details on growth considerations for this system of strain balanced QWs, and development of single and dual junction device designs, will be presented.