Exciton localization and dynamics in GaNAsP nanowires

Abstract

This work investigates exciton localization and dynamics in semiconductor GaNAsP nanowires (NWs) with varying nitrogen concentrations. Through detailed time-resolved photoluminescence studies, we identify a nitrogen composition-dependent difference in exciton transfer between localized states formed due to alloy disorder. With [N] = 0.1%, the localized states exhibit cluster-like, non-interacting behavior, whereas at [N] = 1.1%, a continuous band of localized states is observed. Additionally, the phosphorous incorporation in the NWs appears to enhance the exciton spatial confinement compared to behaviors observed in phosphorous-free GaNAs NWs, emphasizing the role of the alloy composition in the nature of exciton localization. Temperature is highlighted as a significant factor affecting exciton mobility, enabling efficient transfer between the localized states at higher temperatures. This, in turn, influences exciton lifetimes. Our findings, therefore, shed light on the nature of exciton dynamics in GaNAsP NWs, enriching our understanding of these materials and paving the way for their applications in optoelectronics.