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Title: CdSe/ZnS quantum dot size dependent carrier relaxation in hybrid organic/inorganic system
Authors: Uddin, A.
Wong, H. S.
Teo, C. C.
Issue Date: 2012
Source: Uddin, A., Wong, H. S., & Teo, C. C. (2012). CdSe/ZnS Quantum Dot Size Dependent Carrier Relaxation in Hybrid Organic/Inorganic System. Journal of Nanoscience and Nanotechnology, 12(10), 7853-7859(7).
Series/Report no.: Journal of nanoscience and nanotechnology
Abstract: We have studied the CdSe/ZnS quantum dot (QD) size dependent carrier relaxation dynamics in hybrid organic/inorganic system for the first time. The QD size was from 5.0 to 2.0 nm. The optical narrow emission of quantum dots shift to higher energies as the size of dots gets smaller due to the 3-D confinement which splits the continuous band into a series of discrete quantum states and increases the band gap. The carrier relaxation time in QDs was found to increases as the pump power increased and reached saturation at ∼326 μW excitation, probably due to the saturation of traps with the photoexcited charge carriers within individual nanoparticles. The relaxation rate was also increased with pump power, indicating that new relaxation processes e.g., Auger processes and faster carrier trapping were present. The slow decay component remained at the lowest power (51 μW) excitation with no fast decay present. The decrease of CdSe/ZnS QD size increased the fast component relaxation rate probably due to a higher number of surface defects hence inducing faster trapping of carriers by shallow trap state.
DOI: 10.1166/jnn.2012.6615
Fulltext Permission: none
Fulltext Availability: No Fulltext
Appears in Collections:MSE Journal Articles

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