Temperature dependent photoluminescence of single CdS nanowires

Abstract

Temperature dependent photoluminescence (PL) is used to study the electronic properties of single CdS nanowires. At low temperatures, both near-band edge (NBE) photoluminescence (PL) and spatially-localized defect-related PL are observed in many nanowires. The intensity of the defect states is a sensitive tool to judge the character and structural uniformity of nanowires. As the temperature is raised, the defect states rapidly quench at varying rates leaving the NBE PL which dominates up to room temperature.All PL lines from nanowires follow closely the temperature-dependent band edge, similar to that observed in bulk CdS.

Characterization, Cathodoluminescence, and Field‐Emission Properties of Morphology‐Tunable CdS Micro/Nanostructures

“…[20,[40][41][42][43] The two peaks observed in this study can be ascribed to near-band-edge (NBE; 527 nm) and deep-level (DL; 735 nm) emissions. Several different hypotheses have been proposed to explain the origin of the DL emission, including the presence of some self-activated centers, nonstoichimetric defects and impurities.…”

Polarized photoluminescence and time-resolved photoluminescence from single CdS nanosheets

“…As we will show, high resolution transmission electron microscope ͑HR-TEM͒ images provide evidence that the NSs are single crystalline with hexagonal wurtzite structure. Time-resolved PL measurements give exciton recombination lifetimes of ϳ200 ps which are significantly longer than that of the near band edge emission recently observed in single CdS nanowires ͑Ͻ50 ps͒, 10,11 but shorter than the lifetimes observed in bulk CdS crystals. The catalyst-assisted vapor phase transport growth method was used to grow the CdS NSs.…”

A Study of GaAsSb Nanowires by Molecular Beam Epitaxy for Near IR Applications

“…Higher E a at 77 meV has been observed in GaAs NWs grown by Au-assisted catalyst and has generally been assigned to a deep center associated with Au-induced defects [42], which cannot be the case in our NWs since our NWs are Ga catalyzed. Such a deep center has been observed in CdS NWs [43]. The observation of such a deep exciton suggests the presence of the defect complexes in these NWs.…”