Deep levels in p- and n-type InGaAsN for high-efficiency multi-junction III–V solar cells

DLTS measurements have been performed on InGaAsN. Four hole traps have been identified in 1.05 eV, p-type InGaAsN and the removal of a midgap trap (∼0.5 eV) during annealing has been correlated with improved bulk material properties. Improvements in MOCVD growth conditions resulted in a reduction of trap density in 1.05 eV, p-type InGaAsN. Increased indium and nitrogen composition has been correlated with higher defect concentrations in p-type InGaAsN. Two electron traps have been identified in 1.15 eV, n-type InGaAsN and annealing was found to reduce the density of the shallow electron trap.