We study the dynamics of excited carriers in intrinsic and dopedsemiconducting lead chalcogenide nanocrystals and nanowires using thedensity matrix theory. The Liouville-von Neumann equations of motionfor the reduced density matrix are solved for the electrons coupledto an external phonon bath. The time evolutions of the levelpopulations and spatial charge density are followed, providing theinformation about the carrier lifetimes and spatial chargeseparation. Using this information, we address the problems ofradiationless quenching and unexpectedly high carrier decay ratesthat have been observed [1] in nanocrystal and nanorod experiments.The obtained results will be useful for designing new photovoltaicdevices based on lead chalcogenide nanocrystals and nanowires.Acknowledgement:Part of this work was performed under the ASEE program at NRL.[1] J. M. Harbold, H. Du, T. D. Krauss, K. S. Cho, C. B. Murray, and F. W. Wise, Phys. Rev. B 72,  195312 (2005); Z. J. Jiang and D. F. Kelley, J. of Phys. Chem. C 114, 17519 (2010).

Density matrix theory
study of the dynamics of excited carriers in lead chalcogenide
nanocrystals and nanowires

242nd National Meeting (2011)

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Density matrix theory study of the dynamics of excited carriers in lead chalcogenide nanocrystals and nanowires