Optimization of growth and fabrication techniques to enhance the InGaN/GaN multiple quantum well solar cells performance

Two structures of InGaN/GaN multiple quantum well solar cells are grown and fabricated in this work, which are 30 periods In0.14Ga0.86N/GaN (1.72 nm/4.14 nm, sample A) and In0.19Ga0.81N/GaN (2.76 nm/4.14 nm, sample B), respectively. The peak external quantum efficiency of sample A can reach over 60%, which is considered to be related with the longer carrier lifetime. The current density-voltage characteristics show that sample A exhibited an open-circuit voltage of 2.13 V, a short-circuit current density of 2.55 mA/cm2, a fill-factor of 65.7% and a conversion efficiency of 3.56%. Those indicators are among the best up to date as far as we know for InGaN/GaN solar cells.