GaAs solar cell with GaInP window grown by all metalorganic source MOVPE

Tertiarybutylarsine (tBAs) and tertiarybutylphosphine (tBP) are expected as safe alternatives to conventional hazardous hydrides, AsH ₃ and PH₃. We have applied these safer metalorganic precursors to the GaAs solar cell growth and have obtained a cell efficiency of 23.3% (under AM1.5G·100 mW/cm², V _OC=1.025 V, J_SC=26.9 mA/cm², FF=0.843, the conversion efficiency for active area is 25.1%). The cell consists of the GaAs single junction and the lattice-matched GaInP window, and was grown using only metalorganic precursors. The external quantum efficiency of the GaInP window cell in the shorter wavelength range is improved considerably, compared to our previous GaAs cell with AlGaAs window grown with all metalorganic source MOVPE. This improvement is consistent with the results of the interface recombination velocity estimation for GaInP/GaAs interface and AlGaAs/GaAs interface. These results demonstrate that all metalorganic source MOVPE for the GaAs solar cell is a safe and promising alternative to the conventional MOVPE using hydride sources