Minghui Song

Investigation of GaInAs strain reducing layer combined with InAs quantum dots embedded in Ga(In)As subcell of triple junction GaInP/Ga(In)As/Ge solar cell

The InAs/GaAs quantum dots structure embedded in GaInP/Ga(In)As/Ge triple junction solar cell with and without Ga0.90In0.10As strain reducing layer was investigated. Conversion efficiency of 33.91% at 1,000 suns AM 1.5D with Ga0.90In0.10As strain reducing layer was demonstrated. A 1.19% improvement of the conversion efficiency was obtained via inserting the Ga0.90In0.10As strain reducing layer. The main contribution of this improvement was from the increase of the short-circuit current, which is caused by the reduction of the Shockley–Read–Hall recombination centers. Consequently, there was a decrease in open circuit voltage due to the lower thermal activation energy of confined carriers in Ga0.9In0.1As than GaAs and a reduction in the effective band gap of quantum dots.

1 eV In0.3Ga0.7As subcell towards the high-efficiency inverted metamorphic solar cells

On the way to the industrial application of inverted metamorphic triple junction solar cell, the 1 eV In0.3Ga0.7As subcell epitaxial grown by MOCVD on InxGa1−xP graded buffer layers were reported here. The structural analysis of XRD, SEM, TEM, and SIMS were carried out. The I-V and EQE characterizations were measured under the 1000 suns AM 1.5D conditions. Those results extended the industrial vista of the high efficiency, low dislocation density, current matching solar cells.