An investigation on In_xGa_1-xN/GaN multiple quantum well solar cells

The conversion efficiency of In_xGa_1-xN/GaN multiple quantum well solar cells is originally investigated in theory based on the ideal diode model and the ideal unity quantum well model. The results reveal that the conversion efficiency partially depends on the width of the quantum well and the thickness of the barrier region but is dominated by the number of quantum wells and indium content of In_xGa_1-xN. The calculated results are found to be basically trustworthy by comparing with reported experimental results. An In_0.15Ga_0.85N/GaN multiple quantum well solar cell is successfully fabricated with a conversion efficiency of 0.2%. The main discrepancy between calculated and experimental results is the material quality and manufacturing technology which need to be improved.