Theory of multiexciton generation in semiconductor nanocrystals

Abstract

We develop a generalized framework based on a Green's function formalism to calculate the efficiency of multiexciton gen-eration in nanocrystal quantum dots. The direct/indirect absorption and coherent/incoherent impact ionization mechanisms, often used to describe multiexciton generation in nanocrystals, are reviewed and rederived from the unified theory as certain approximations. In addition, two new limits are described systematically - the weak Coulomb coupling limit and the semi-wide band limit. We show that the description of multiexciton generation in nanocrystals can be described as incoherent process and we discuss the scaling of multiexciton generation with respect to the photon energy and nanocrystal size. Illustrations are given for three prototype systems: CdSe, InAs and silicon quantum dots.

9 pages, 5 figures

References in corpus (4)

• Carrier multiplication yields in PbS and PbSe nanocrystals measured by transient photoluminescence
• Carrier multiplication yields in CdSe and CdTe nanocrystals by transient photoluminescence
• Distribution of carrier multiplication rates in CdSe and InAs nanocrystals
• Impact Excitation by Hot Carriers in Carbon Nanotubes

Cited by in corpus (15)

• Carrier multiplication between interacting nanocrystals for fostering silicon-based photovoltaics
• Effect of dot size on exciton binding energy and electron-hole recombination probability in CdSe quantum dots
• Electron-hole correlations govern Auger recombination in nanostructures
• Origins of singlet fission in solid pentacene from an ab initio Green's-function approach
• Size Dependence of the Multiple Exciton Generation Rate in CdSe Quantum Dots
• Ultrafast supercontinuum spectroscopy of carrier multiplication and biexcitonic effects in excited states of PbS quantum dots
• Numerical Study of Carrier Multiplication Pathways in Nanocrystalline and Bulk Form of PbSe
• Simulations of nonradiative processes in semiconductor nanocrystals
• Biexciton generation rates in CdSe nanorods are length independent
• Numerical analysis of carrier multiplication mechanisms in nanocrystal and bulk forms of PbSe and PbS
• Coulomb matrix elements for the impact ionization process in nanocrystals: the envelope function approach
• Entropy production in a photovoltaic cell
• Ab Initio Modeling of Phonon-Assisted Relaxation of Electrons and Excitons in Semiconductor Nanocrystals for Multiexciton Generation
• Dynamics of dissipative multiple exciton generation in nanocrystals
• Carrier Multiplication in Silicon Nanocrystals: Theoretical Methodologies and Role of the Passivation