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 ( s imilar to 0.5 eV) during annealing has been correlated with improved bulk m aterial properties. Improvements in MOCVD growth conditions resulted in a r eduction of trap density in 1.05 eV, p-type InGaAsN. Increased indium and n itrogen composition has been correlated with higher defect concentrations i n p-type InGaAsN. Two electron traps have been identified in 1.15 eV, n-typ e InGaAsN and annealing was found to reduce the density of the shallow elec tron trap. (C) 2001 Elsevier Science B.V. All rights reserved.